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Hi guys, today we are going to study about physical quantites. Physical quantity is any physical property of a material or system that can be quantified. A physical quantity has been assigned a unit to measure that particular quantity and the unit has a fixed reference value. Let&#39;s know more about this.

<h2>Physical quantity:</h2>

To measure a physical quantity like length, mass and time we require a standard of measurement. This standard of measurement is called the unit of that physical quantity. For example, the unit of length is meters and a standard length of 1 metre has a precise definition. To measure the length of an object is to determine how many times this standard- length meter is contained in the length of a room. The comparison of a physical quantity with a standard quantity is called measurement.

All those quantities that can be measured directly or indirectly and in terms of which the laws of physics can be expressed are called physical quantities. Physical quantities can be fundamental or derived.

Fundamental Physical Quantities: Which can be treated as independent of other physical quantities and are not usually defined in terms of other physical quantities are called fundamental quantities. There are seven fundamental or base quantities, they are:

<ul>
	<li>Mass</li>
	<li>Length</li>
	<li>Time</li>
	<li>Electric current</li>
	<li>Temperature</li>
	<li>Luminous intensity</li>
	<li>Amount of substance</li>
</ul>

Derived Physical Quantities: The physical quantities whose defining operations are based on other physical quantities are called derived quantities. What it means is that the derived quantities are actually a derivation using the fundamental physical quantities and hence are not independent.

<h2>Measurement:</h2>

Measurement of a physical quantity is the process of comparing this quantity with a standard amount of the physical quantity of the same kind, called its unit. To express the measurements of a physical quantity, we need to know two things:

<ul>
	<li>The unit in which the quantity is measured.</li>
	<li>The numerical value or the magnitude of the quantity (the number of times that unit is contained in the given physical quantity.)</li>
</ul>

Physical Unit:

The standard amount of a physical quantity chosen to measure the physical quantity of the same kind is called a physical quantity. There are certain properties of a unit:

<ol>
	<li>The unit should be of some suitable size.</li>
	<li>The unit must be well-defined.</li>
	<li>The unit should be easily reproducible at all places.</li>
	<li>The unit must not change with time.</li>
	<li>The unit should not change with physical conditions like temperature, pressure etc.</li>
	<li>The unit must be easily comparable experimentally with similar physical quantities.</li>
</ol>

Fundamental Unit:

The physical units which can neither be derived from one another, nor they can be further resolved into more simpler units are called fundamental quantities. The units of fundamental quantities are fundamental units.

Derived Unit:

All other physical units which can be expressed in terms of fundamental units are called derived units. Like: Speed = distance/ time

Unit of speed = unit of distance traveled/unit of time

= meter/second

= ms-1

<h2>System of units:</h2>

A complete set of units which is used to measure all kinds of fundamental and derived quantities is called a system of units.

(1) FPS System: In this system, the unit of length is Foot, unit of mass is Pound and the unit of time is Second.

(2) CGS System: In this system, the units of length, mass and time are Centimeter, Gram and Second, respectively.

(3) MKS System: In this system, the unit of length, mass and time are Meters, Kilogram and Second, respectively.

(4) SI System: This system is widely used in all measurements throughout the world. The system is based on seven basic units and two supplementary units.

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none">
	<tbody>
		<tr>
			<td>
			S.no.
			</td>
			<td>
			Basic physical quantity
			</td>
			<td>
			Basic unit
			</td>
			<td>
			Symbol
			</td>
		</tr>
		<tr>
			<td>
			1.
			</td>
			<td>
			length
			</td>
			<td>
			metre
			</td>
			<td>
			m
			</td>
		</tr>
		<tr>
			<td>
			2
			</td>
			<td>
			mass
			</td>
			<td>
			kilogram
			</td>
			<td>
			kg
			</td>
		</tr>
		<tr>
			<td>
			3.
			</td>
			<td>
			time
			</td>
			<td>
			second
			</td>
			<td>
			s
			</td>
		</tr>
		<tr>
			<td>
			4.
			</td>
			<td>
			temperature
			</td>
			<td>
			kelvin
			</td>
			<td>
			K
			</td>
		</tr>
		<tr>
			<td>
			5.
			</td>
			<td>
			Electric current
			</td>
			<td>
			ampere
			</td>
			<td>
			A
			</td>
		</tr>
		<tr>
			<td>
			6.
			</td>
			<td>
			Luminous intensity
			</td>
			<td>
			candela
			</td>
			<td>
			cd
			</td>
		</tr>
		<tr>
			<td>
			7.
			</td>
			<td>
			Quantity of matter
			</td>
			<td>
			mole
			</td>
			<td>
			mol
			</td>
		</tr>
	</tbody>
</table>

<h2>Abbreviations for the power of ten:</h2>

When the magnitude of the physical quantities is very large or very small, it is convenient to express them in the multiples or submultiples of the SI units.

Prefixes for powers of ten:

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:14px">
	<tbody>
		<tr>
			<td>
			 

			Multiple
			</td>
			<td>
			 

			Prefix
			</td>
			<td>
			 

			Sym bol
			</td>
			<td>
			 

			Sub- multiple
			</td>
			<td>
			 

			Prefix
			</td>
			<td>
			 

			Symbol
			</td>
		</tr>
		<tr>
			<td>
			 

			101
			</td>
			<td>
			 

			deca
			</td>
			<td>
			 

			da
			</td>
			<td>
			 

			10-1
			</td>
			<td>
			 

			Deci
			</td>
			<td>
			 

			d
			</td>
		</tr>
		<tr>
			<td>
			 

			102
			</td>
			<td>
			 

			hecto
			</td>
			<td>
			 

			h
			</td>
			<td>
			 

			10-2
			</td>
			<td>
			 

			Centi
			</td>
			<td>
			 

			c
			</td>
		</tr>
		<tr>
			<td>
			 

			103
			</td>
			<td>
			 

			kilo
			</td>
			<td>
			 

			k
			</td>
			<td>
			 

			10-3
			</td>
			<td>
			 

			milli
			</td>
			<td>
			 

			m
			</td>
		</tr>
		<tr>
			<td>
			 

			106
			</td>
			<td>
			 

			mega
			</td>
			<td>
			 

			M
			</td>
			<td>
			 

			10-6
			</td>
			<td>
			 

			micro
			</td>
			<td>
			 

			µ
			</td>
		</tr>
		<tr>
			<td>
			 

			109
			</td>
			<td>
			 

			giga
			</td>
			<td>
			 

			G
			</td>
			<td>
			 

			10-9
			</td>
			<td>
			 

			nano
			</td>
			<td>
			 

			n
			</td>
		</tr>
		<tr>
			<td>
			 

			1012
			</td>
			<td>
			 

			tera
			</td>
			<td>
			 

			T
			</td>
			<td>
			 

			10-12
			</td>
			<td>
			 

			pico
			</td>
			<td>
			 

			p
			</td>
		</tr>
		<tr>
			<td>
			 

			1015
			</td>
			<td>
			 

			peta
			</td>
			<td>
			 

			P
			</td>
			<td>
			 

			10-15
			</td>
			<td>
			 

			femto
			</td>
			<td>
			 

			f
			</td>
		</tr>
		<tr>
			<td>
			 

			1018
			</td>
			<td>
			 

			Exa
			</td>
			<td>
			 

			E
			</td>
			<td>
			 

			10-18
			</td>
			<td>
			 

			Atto
			</td>
			<td>
			 

			a
			</td>
		</tr>
	</tbody>
</table>

I hope this blog helped you to clear your queries related to this topic. Stay tuned for more blogs.

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Learn&nbsp;the&nbsp;key concepts of units.

Learn the key concepts of Science topic -  Units

इकाई - प्रमुख अवधारणाओं को सीखें और उनका अभ्यास करें

Today we will be studying about animal kingdom. Every day we come across a number of animals. These organisms, varying from sponges to sharks, ants to whales, earthworms to anacondas, all belong to the same group. i.e., Kingdom Animalia. Let&#39;s dive deep and learn thoroughly.

<h2>Kingdom Animalia</h2>

The kingdom Animalia is characterised by heterotrophic eukaryotic organisms that are multicellular and their cells lack a cell wall.

(i) Heterotrophic Nutrition: All animals are heterotrophs. They directly or indirectly depend on plants for food. Ex. Lions eat deers and deers eat grass

(ii) Holozoic Mode of Nutrition: Nutrition involving engulfment of the whole or part of a plant or an animal either in solid or in liquid state is called animal like or holozoic nutrition.

(iii) Multicellular: All are multicellular. Their body is made up of more than one cell

(iv) Growth: Animals show a definite growth pattern from birth to death. All of them grow into adults that have a definite shape and size

(v) Reproduction: Sexual reproduction is the major mode of reproduction which includes copulation between male and female followed by embryological development.

Basis of Classification:

Inspite of differences in the structure and form of different animals, there are certain fundamental features which are common to various individuals in relation to:

<ol>
	<li>Levels of organisation also called grades of organisation</li>
	<li>Patterns of digestive circulatory or reproductive system</li>
	<li>Body symmetry</li>
	<li>Number of germ layers during embryonic development</li>
	<li>Nature of coelom or body cavity</li>
	<li>Presence or absence of segmentation in the body</li>
	<li>Presence or absence of notochord.</li>
</ol>

<h2>Classification of animals</h2>

For a systematic study of animals, they are divided into various minor and major groups on the basis of similarities and differences and each group is given a particular name depending upon its characteristics. Various levels of classification of complexity in decreasing order can be shown as: Kingdom —› phylum —› class —› order —› family —› genus —› species

Basically, the kingdom animalia is divided into the following ‘11’ phyla: (1) Porifera (2) Coelenterata (Cnidaria) (3) Ctenophora (4) Platyhelminthes (5) Aschelminthes (6) Annelida (7) Arthropoda (8) Mollusca (9) Echinodermata (10) Hemichordata (11) Chordata

<h2>Phylum – Porifera</h2>

Members of this phylum are commonly known as sponges. They are also known as ‘pore bearers’ as their body walls possess numerous tiny pores.

<h2>Phylum –Coelenterata (Cnidaria)</h2>

General features:

<ol>
	<li>Habitat: They are mostly marine but few are freshwater inhabitants (eg. Hydra)</li>
	<li>Habit: There are two types of Habit: a) Solitary: Those animals which live singly and are independent. Ex. Hydra b) Colonial: Those animals which live in the association of other individuals of the same type. Ex.physania, gorgonia, obelia</li>
	<li>Body symmetry: The coelenterates are the radially symmetrical animals.</li>
	<li>Level of organisation: They exhibit the tissue level of organisation. The tissues are arranged variously to perform the basic functions in their body.</li>
	<li>Germ layers: These are the diploblastic animals as cells in their embryonic stages are arranged in two layers, outer ectoderm, Inner endoderm with an intervening gelatinous layer mesoglea. This mesoglea provides the jelly-like form to some coelenterates.</li>
	<li>Digestive tract: The body of coelenterates bear a central gastro-vascular cavity which opens to the outside through a single opening called mouth.</li>
	<li>Skeleton: Some of the cnidarians, e.g., corals have a hard skeleton composed of calcium carbonate.</li>
	<li>Body forms: Two basic body forms are in cnidarians which differ in the structure and function from one another. These are called polyp and medusa Examples: physalia, adamsia, pennatula, meandrina</li>
</ol>

<h2>Phylum- Platyhelminthes</h2>

General features:

<ol>
	<li>Habit and Habitat: These are mostly endoparasites. Mostly aquatic, some may be terrestrial also.</li>
	<li>Body symmetry: bilaterally symmetrical.</li>
	<li>Level of organisation: organ level</li>
	<li>Germ layers: triploblastic</li>
	<li>Coelom: acoelomate</li>
	<li>Body form: dorsoventrally flattened body Examples: Liver fluke, Tapeworm, Planaria.</li>
</ol>

<h2>Phylum- Aschelminthes (Nematoda)</h2>

They are commonly called roundworms. General features:

<ol>
	<li>Habit and Habitat: free living or parasitic. May be aquatic or terrestrial.</li>
	<li>Body symmetry: bilaterally symmetrical.</li>
	<li>Level of organisation: organ level</li>
	<li>Germ layers: triploblastic</li>
	<li>Coelom: ‘pseudocoelomates’</li>
	<li>Body form: elongated cylindrical body</li>
	<li>Digestive system: these have well-developed muscular pharynx.</li>
	<li>Excretory system: excretory tube along with renette cell removes the body waste.</li>
	<li>Fertilization: internal Examples: ascaris(roundworm), wuchereria, ancylostoma (hookworm).</li>
</ol>

<h2>Phylum- Annelida </h2>

General features:

<ol>
	<li>Habit and habitat: may be aquatic or terrestrial </li>
	<li>Body symmetry: bilateral symmetry</li>
	<li>Level of organisation: organ system level</li>
	<li>Germ layers: triploblastic animals</li>
	<li>Locomotion: have the capability to locomote.</li>
	<li>Segmentation: body is metamerically segmented, body segments are called metamers.</li>
	<li>Body form: segmented body</li>
	<li>Digestive system: it is complete, and entirely extracellular.</li>
	<li>Circulatory system: closed type.</li>
	<li>Excretory system: nephridia help in excretion as well as osmoregulation.</li>
	<li>Nervous system: Body control is provided by the nervous system consisting of paired ganglia</li>
	<li>Reproductive system: Earthworms and leeches are monoecious. Example: neries (sandworm), pheretima (earthworm), hirudinaria</li>
</ol>

<h2>Phylum- Arthropoda</h2>

It is the largest phylum of the animal kingdom. General features:

<ol>
	<li>Habit and habitat: oceans- limulus, freshwater- daphnia, land-cockroach</li>
	<li>Body symmetry- bilaterally symmetrical</li>
	<li>Level of organisation- organ system</li>
	<li>Germ layers- triploblastic animals</li>
	<li>Coelom- true coelom present, hence -coelomates</li>
	<li>Segmentation: body is segmented</li>
	<li>Body form: the body of them is covered by hard, waterproof exoskeleton made up of chitin.</li>
	<li>Digestive system: tract is complete and has glands</li>
	<li>Circulatory system: circulatory is of open type.</li>
	<li>Excretory system: through malpighian tubules.</li>
	<li>Reproductive system: these are mostly dioecious. The females are mostly oviparous.</li>
</ol>

<h2>Phylum- Mollusca</h2>

General features:

<ol>
	<li>Habit and habitat: Marine and Freshwater bodies</li>
	<li>Body symmetry- bilaterally symmetrical</li>
	<li>Level of organisation- organ system</li>
	<li>Germ layers- triploblastic animals</li>
	<li>Coelom- true coelom present, hence -coelomates</li>
	<li>Segmentation: body is unsegmented</li>
	<li>Body form: soft fleshy body</li>
	<li>Digestive system: tract is complete and has glands</li>
	<li>Circulatory system: circulatory is of open type.</li>
	<li>Excretory system: through metanephridia Examples: Octopus, Snails, Chiton, Mussels</li>
</ol>

<h2>Phylum- Echinobermata</h2>

General features:

<ol>
	<li>Habit and habitat: Exclusively Marine</li>
	<li>Body symmetry- bilaterally symmetrical</li>
	<li>Level of organisation- organ system</li>
	<li>Germ layers- triploblastic animals</li>
	<li>Coelom- true coelom present, hence -coelomates</li>
	<li>Segmentation: body is unsegmented</li>
	<li>Body form: Spiny skinned organisms usually with a skeleton made up of calcium carbonate.</li>
	<li>Nervous system: Simple radial nervous system</li>
	<li>Circulatory system: circulatory is of open type.</li>
	<li>Excretory system: through metanephridia</li>
	<li>Reproductive system: They reproduce sexually through gametic fusion and asexually through regeneration. Fertilization is external. Examples: Sea cucumber, Sea urchins, sea stars</li>
</ol>

<h2>Phylum- Hemichordata</h2>

General features:

<ol>
	<li>Habit and habitat: exclusively marine</li>
	<li>Body symmetry- bilaterally symmetrical</li>
	<li>Level of organisation- organ system</li>
	<li>Germ layers- triploblastic animals</li>
	<li>Coelom- true coelom present, hence -coelomates</li>
	<li>Segmentation: segmentation is absent</li>
	<li>Body form: these animals have a very soft, fragile and worm-like appearance.</li>
</ol>

<h2>Phylum chordata</h2>

Animals in this kingdom have four characteristics i.e. notochord, dorsal hollow nerve cord, pharyngeal and post anal tail. It is divided into 3 distinct regions i.e. proboscis, collar, trunk.

(1) Cephalochordata: • members are exclusively marine • notochord extends from head to tail region Example: branchiostoma/amphioxus/lancelet.

(2) Vertebrata: • possess notochord during embryonic period • The notochord is replaced by a cartilaginous or bony vertebral column in the adult.

Class- Cyclostomata • all are ectoparasites • have sucking and circular mouth • body is devoid of scales • paired fins absent • migrate to freshwater for spawning. Examples: petromyzon(lamprey), myxine(hagfish)

A) Class- Chondrichthyes: • marine animals with streamlined body • skin is tough, containing minute placoid scales • These animals are predaceous. • They swim constantly. • heart is two chambered Examples: torpedo (electric organ), Trygon(stingray), scoliodon(dog fish), pristis(saw fish).

B) Class- Osteichthyes: • body is streamlined • four pairs of gills present an air bladder is present which regulates buoyancy. • cold blooded animals. • sexes are separate Examples: marine- exocoetus (flying fish) Freshwater- labeo (rohu) Aquarium- betta (fighting fish)

C) Class- Amphibia: • have two pairs of limbs • can survive both in water and on land • skin is moist (without scales) • ‘tympanum’ represents ear • oviparous and development is indirect Examples: bufo (toad), rana (frog), hyla (tree frog), ichthyophis (limbless amphibia).

Thisc was all about Animal Kingdom. Hope you all your question related to this topic is clear. Stay connected for more such blogs.

Learn the key concepts of Animal kingdom!

Learn the key concepts of Science topic -  Animal kingdom

पशु साम्राज्य - प्रमुख अवधारणाओं को सीखें और अभ्यास करें

Today we will be discussing about biotechnology and see how it can have various uses of organisms to produce useful products. Then, we’ll take a closer look at applications of it. So let&#39;s start. 

Biotechnology is a multidisciplinary field which has a major impact on humankind. This technology has been known since time immemorial. It is concerned with the working of cells or cell- originated molecules for various applications. The term “biotechnology” which is often referred to as “biotech,” was first used by Hungarian engineer Karl Ereky in 1919. It means the production of products from raw materials with the aid of living organisms. He was also known as the father of biotechnology. The European Federation of Biotechnology has given the definition of biotechnology as follows: "Biotechnology is the integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services."

<h2>History of biotechnology</h2>

Biotechnology has existed for thousands of years from an era when humans first learned to produce bread, beer, and wine using the natural process of fermentation. For many past years, the principles of biotechnology were restricted to agriculture, such as harvesting better crops and increasing yields by using good seeds and breeding livestock. Some of the important spotlights are mentioned below:

Principles of Biotechnology:

Today modern biotechnology is based on two major techniques that are namely:

(i) Genetic engineering: Genetic engineering is the manipulation of an organism’s gene by the utility of biotechnology that is used to alter the genetic framework of the cell. The combination of technologies are used for the genetic framework of the cells that includes the transfer of genes in the species limits for the fabrication of improved organisms called clones resulting in gene cloning.

(ii) Maintenance of a sterile environment in chemical engineering: It aids in the growth of only those microorganisms that are needed and this procedure helps in the development of vaccines, antibiotics, drugs, etc.

Basic Principles of Biotechnology: Genetic engineering consists of the isolation and introduction of only those genes into an organism that are desired and eliminates the undesirable genes. The steps included in genetic engineering are as:

<ol>
	<li>Development of recombinant DNA (rDNA).</li>
	<li>Cloning of the desired gene.</li>
	<li>Transfer of the cloned gene into the suitable organism.</li>
</ol>

<h2>Tools for genetic engineering</h2>

Origin of replication (ori): It is a section of DNA sequence which is acknowledged by a cell’s DNA replication proteins that allows initiation of new DNA synthesis. The foreign DNA that is inserted into the Host organism requires to be connected to the origin of relocation and this results in the development of multiple copies of the DNA while if the foreign gene is not attached to the origin of replication then it may not result in the multiplication of DNA.

Antibiotic resistance gene: In the case of some specific microbes, there are several genes that have the ability to grow in the presence of specific antibiotics while the genes give resistance against them. These genes are generally located on the plasmids and are used in the cloning and transformation process.

Restriction Enzymes: The restriction enzymes are responsible for the cutting of DNA Fragments at specific sites. They are also known as “molecular scissors”. These enzymes chop the DNA at a particular site which is specific for each restriction enzyme. They aid in the process of cutting the tranquilized gene which is then inserted into the specific sites of the host. These enzymes cut DNA fragments at their particular Recognition sequences.

Recognition sequences: This sequence is the bases of the DNA sequence that are specific for each restriction enzyme and act as the site for restriction or cutting resulting in the formation of the palindromic sequences.

There are two types of restriction enzymes- Endonucleases and Exonucleases.

Endonucleases: are responsible for the cutting of DNA from the middle. Examples of restriction endonucleases are ECoR1, Hind III, etc. Each endonuclease characterized the restriction site by a specific recognition sequence. Restriction endonucleases are responsible for identification of the specific palindromic nucleotide sequence in the DNA.

Vectors: A vector is any vehicle like virus or plasmid that is used to transport a desired DNA sequence into a host cell as part of a molecular cloning process. The four main types of vectors are plasmids, viral vectors, cosmids, and artificial chromosomes. Out of these, the most commonly used vectors are plasmids.

Host organism: where the recombinant DNA is introduced. The host organism is the ultimate tool of recombinant DNA technology that takes in the vector engineered with the desired DNA with the help of the enzymes. There are various ways in which these recombinant DNAs are inserted into the host namely microinjection, biolistics or gene gun, alternate cooling and heating, use of calcium ions, etc..

<h2>Applications of biotechnology</h2>

Biotechnology is a technology that uses biological systems, living organisms or parts to develop or create useful products. Biotechnology deals with industrial scale construction of biopharmaceuticals and biologicals using genetically modified Microorganisms, fungi, plants and animals. The applications of biotechnology consist of therapeutics, diagnostics, and genetically modified crops for agriculture, processed food, bioremediation, waste treatment, and energy production.

Genetically Modified Organisms (GMO): Plants, bacteria, fungi and animals whose genes have been altered are called Genetically Modified Organisms (GMO). GM plants have a variety of uses. The Genetic modification has advantages such as:

<ul>
	<li>Crops made are more tolerant to abiotic stresses (cold, drought, salt, heat).</li>
	<li>Decreased reliance on chemical pesticides (pest-resistant crops).</li>
	<li>Aided to decrease post-harvest losses.</li>
</ul>

Genetically modified bio-pesticide: Bt toxin is produced by a bacterium known as Bacillus thuringiensis (Bt for short).

Pest resistant plants: Various nematodes parasite a wide variety of plants and animals including human beings.

A nematode Meloidogyne incognita infects the roots of tobacco plants and causes a great loss in yield. A brilliant strategy was adopted to prevent this infestation based on the process of RNA interference (RNAi). RNAi takes place in all eukaryotic organisms as a technique of cellular defense. This technique includes silencing of a specific mRNA due to a complementary dsRNA molecule that binds to and prevents translation of the mRNA (silencing).

Medicine: The recombinant DNA technology processes have made a deep impact in the area of healthcare. It aids in mass production of safe and more effective therapeutic drugs. The recombinant therapeutics do not induce undesired immunological responses.

Genetically Engineered Insulin: Management of adult-onset diabetes is attained by taking insulin regularly. Insulin consists of 2 short polypeptide chains: chain A and chain B which are linked together by disulphide bridges. In mammals including humans, insulin is manufactured as a prohormone. The pro-hormone also requires to be processed before it becomes a fully mature and functional 93 hormone which consists of an extra stretch known as the C peptide.

Diagnosis of HIV: PCR is an important technique to identify many dangerous genetic disorders. Polymerase Chain Reaction (PCR) is presently regularly used to detect HIV in suspected AIDS patients. It is being used to check on the mutations in genes in suspected cancer patients also.

ELISA is based on the principle of antigen-antibody interaction. Infection caused by pathogens can be detected by the presence of antigens like proteins, glycoproteins, etc. or by detecting the antibodies developed against the pathogen.

CRISPR Technology: CRISPR technology is a simple and vital tool for editing genomes. This tool permits scientists to easily alter DNA sequences and modify gene function. CRISPR-Cas9 was developed from a naturally occurring genome editing system in bacteria. The bacteria seize fragments of DNA from invading viruses and utilize them to create DNA segments known as CRISPR arrays. The CRISPR arrays permit the bacteria to remember the viruses. If the viruses attack again, the bacteria produce RNA fragments from the CRISPR arrays that target the viruses’ DNA. CRISPR technology is used on a wide variety of diseases, including single-gene disorders such as cystic fibrosis, hemophilia, and sickle cell disease.

Transgenic Animals: Transgenic animals are those animals whose DNA is manipulated to possess and express an extra foreign gene. Transgenic rats, rabbits, pigs, sheep, cows and fish have been created.

Normal physiology and development: Transgenic animals are designed to help in the study of how genes are regulated, and how they affect the functions of the body and its development. For example, study of complex factors involved in growth such as insulin-like growth factors.

<h2>Biotechnology in India</h2>

The Department of Biotechnology under the Ministry of Science and Technology controls most of the programmes of the biotechnology sector in India. The main goals of this section are:

<ol>
	<li>To deliver services in the areas of research, infrastructure, generation of human resource, popularization of biotechnology, promotion of industries etc.</li>
	<li>Implementation of biosafety guidelines for genetically modified organisms, recombinant DNA products and biotechnology-based programs for societal profits.</li>
	<li>To build an information network for the Bioinformatics mission of India in the scientific community, nationally as well as internationally.</li>
</ol>

Genetic Engineering Appraisal Committee: The Genetic Engineering Appraisal Committee is apex biotechnology regulatory body in India. The GEAC works under the Ministry of Environment, Forest and Climate Change (MoEF&CC). This committee is responsible for the appraisal of activities that include large-scale use of dangerous microbes and recombinants in research and industrial production from the environmental angle. The committee is also responsible for the appraisal of proposals connecting to the release of genetically engineered organisms and products into the environment which contains experimental field trials.

Application of biotechnology is a major tool for development all over the world. Intertwined with culture and socio-ethical values, biotechnology could be useful in solving future problems like food and water insecurity that obstruct national development and threaten peace in the developing world. This was all about biotechnology and its applications. Hoping all your doubts are clear. Stay tunned.

Learn the key concepts of Biotechnology

Learn the key concepts of Science topic -  Biotechnology

जैव प्रौद्योगिकी- प्रमुख अवधारणाओं को सीखें और अभ्यास करें

Hello learner, hope you are doing great. Today we will be studying about the Dimensions of Physical quantity.

Let&#39;s firstly know what is dimensions of a physical quantity. Dimensions of a physical quantity are the powers or exponents to which the fundamental quantities must be raised to represent that quantity completely. Suppose there is a new quantity (a quantity for which the dimensional formula is unknown). Now if we want to derive a dimensional formula for this particular quantity, we would have used the fundamental quantities that we already know and we have to raise the fundamental quantities to a certain power (or exponents) in order to derive dimensions of this new quantity. For example, Density = mass/volume, Dimensions of density = [ML-3 ] = [M1L -3T 0 ]

All the derived physical quantities of the world can be expressed in terms of some combinations of the seven fundamental or base quantities. We call these fundamental quantities as the seven dimensions of the world, they are

<ol>
	<li>Dimension of length = [L]</li>
	<li>Dimension of mass = [M]</li>
	<li>Dimension of time = [T]</li>
	<li>Dimension of electric current = [A]</li>
	<li>Dimension of thermodynamic temperature = [K]</li>
	<li>Dimension of luminous intensity = [cd]</li>
	<li>Dimension of amount of substance = [mol]</li>
</ol>

Dimensional Formula:

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:14px; width:300px">
	<tbody>
		<tr>
			<td>
			Sr.

			No.
			</td>
			<td>
			Physical Quantity
			</td>
			<td>
			Relation with other quantities
			</td>
			<td>
			Dimensional formula
			</td>
			<td>
			SI Unit 
			</td>
		</tr>
		<tr>
			<td>
			1
			</td>
			<td>
			area
			</td>
			<td>
			Length × breadth
			</td>
			<td>
			[M0L2T0 ]
			</td>
			<td>
			m2
			</td>
		</tr>
		<tr>
			<td>
			2
			</td>
			<td>
			volume
			</td>
			<td>
			Length × breadth × height
			</td>
			<td>
			[M0L3T0 ]
			</td>
			<td>
			m3
			</td>
		</tr>
		<tr>
			<td>
			3
			</td>
			<td>
			density
			</td>
			<td>
			Mass / volume
			</td>
			<td>
			[ML-3T0 ]
			</td>
			<td>
			Kg m-3
			</td>
		</tr>
		<tr>
			<td>
			4
			</td>
			<td>
			Speed or velocity
			</td>
			<td>
			Distance / time
			</td>
			<td>
			[M0LT-1 ]
			</td>
			<td>
			m s-1
			</td>
		</tr>
		<tr>
			<td>
			5
			</td>
			<td>
			accelerati on
			</td>
			<td>
			Change in velocity / time
			</td>
			<td>
			[M0LT-2 ]
			</td>
			<td>
			m s-2
			</td>
		</tr>
		<tr>
			<td>
			6
			</td>
			<td>
			momentu m
			</td>
			<td>
			Mass × velocity
			</td>
			<td>
			[MLT-1]
			</td>
			<td>
			Kg
			</td>
		</tr>
		<tr>
			<td>
			7
			</td>
			<td>
			force
			</td>
			<td>
			Mass × acceleration
			</td>
			<td>
			[MLT-2]
			</td>
			<td>
			N
			</td>
		</tr>
		<tr>
			<td>
			8
			</td>
			<td>
			work
			</td>
			<td>
			Force × distance
			</td>
			<td>
			[ML2T-2 ]
			</td>
			<td>
			J
			</td>
		</tr>
		<tr>
			<td>
			9
			</td>
			<td>
			energy
			</td>
			<td>
			Amount of work
			</td>
			<td>
			[ML2T-2 ]
			</td>
			<td>
			J
			</td>
		</tr>
		<tr>
			<td>
			10
			</td>
			<td>
			power
			</td>
			<td>
			Work / time
			</td>
			<td>
			[ML2T-3 ]
			</td>
			<td>
			W
			</td>
		</tr>
		<tr>
			<td>
			11
			</td>
			<td>
			pressure
			</td>
			<td>
			Force / area
			</td>
			<td>
			[ML-1T-2]
			</td>
			<td>
			Pa
			</td>
		</tr>
		<tr>
			<td>
			12
			</td>
			<td>
			Gravitation al constant ‘G’
			</td>
			<td>
			[Force × (distance)2] ÷ [mass × mass]
			</td>
			<td>
			[M-1L3T-2]
			</td>
			<td>
			Nm2kg-2
			</td>
		</tr>
		<tr>
			<td>
			13
			</td>
			<td>
			stress
			</td>
			<td>
			Force / area
			</td>
			<td>
			[ML-1T-2]
			</td>
			<td>
			Nm-2
			</td>
		</tr>
		<tr>
			<td>
			14
			</td>
			<td>
			strain
			</td>
			<td>
			Change in dimension / original dimension
			</td>
			<td>
			Dimensionle ss
			</td>
			<td>
			-
			</td>
		</tr>
		<tr>
			<td>
			15
			</td>
			<td>
			Coefficient of elasticity
			</td>
			<td>
			Stress / strain
			</td>
			<td>
			[ML-1T-2]
			</td>
			<td>
			Nm-2
			</td>
		</tr>
		<tr>
			<td>
			16
			</td>
			<td>
			angle
			</td>
			<td>
			Arc / radius
			</td>
			<td>
			Dimensionle ss
			</td>
			<td>
			-
			</td>
		</tr>
		<tr>
			<td>
			17
			</td>
			<td>
			angular velocity
			</td>
			<td>
			Angle / time
			</td>
			<td>
			[M0L0T-2]
			</td>
			<td>
			Rad s-1
			</td>
		</tr>
		<tr>
			<td>
			18
			</td>
			<td>
			Moment of inertia
			</td>
			<td>
			Mass × (distance)2
			</td>
			<td>
			[ML2T0]
			</td>
			<td>
			Kg m2
			</td>
		</tr>
		<tr>
			<td>
			19
			</td>
			<td>
			frequency
			</td>
			<td>
			1 / time period
			</td>
			<td>
			[M0L0T-1]
			</td>
			<td>
			s-1 or Hz
			</td>
		</tr>
		<tr>
			<td>
			20
			</td>
			<td>
			Plank&#39;s constant
			</td>
			<td>
			Energy / frequency
			</td>
			<td>
			[ML2T-1]
			</td>
			<td>
			Js
			</td>
		</tr>
		<tr>
			<td>
			21
			</td>
			<td>
			Relative density
			</td>
			<td>
			Density of substance / density of water
			</td>
			<td>
			Dimensionle ss
			</td>
			<td>
			-
			</td>
		</tr>
		<tr>
			<td>
			22
			</td>
			<td>
			Heat or enthalpy
			</td>
			<td>
			energy
			</td>
			<td>
			[ML2T-2]
			</td>
			<td>
			J
			</td>
		</tr>
		<tr>
			<td>
			23
			</td>
			<td>
			Thermal conductivit y
			</td>
			<td>
			(Heat × distance)

			/ (area × temp. × time)
			</td>
			<td>
			[MLT-3K-1]
			</td>
			<td>
			Js-1m-1 k-1
			</td>
		</tr>
		<tr>
			<td>
			24
			</td>
			<td>
			Universal gas constant
			</td>
			<td>
			PV/nT
			</td>
			<td>
			[ML2T-2K-1 mol-1]
			</td>
			<td>
			Jmol-1 k-1
			</td>
		</tr>
		<tr>
			<td>
			25
			</td>
			<td>
			Boltzman n&#39;s constant
			</td>
			<td>
			Energy / temperature
			</td>
			<td>
			[ML2T-2K-1]
			</td>
			<td>
			JK-1
			</td>
		</tr>
		<tr>
			<td>
			26
			</td>
			<td>
			Stefan&#39;s constant
			</td>
			<td>
			Energy / [area

			× time × (temp)2]
			</td>
			<td>
			[ML0T-3K-4]
			</td>
			<td>
			Js-1m-4 K-4
			</td>
		</tr>
		<tr>
			<td>
			27
			</td>
			<td>
			Electric charge
			</td>
			<td>
			Time × current
			</td>
			<td>
			[M0L0TA]
			</td>
			<td>
			C

			(coulom b)
			</td>
		</tr>
		<tr>
			<td>
			28
			</td>
			<td>
			Electric potential
			</td>
			<td>
			Work / charge
			</td>
			<td>
			[ML2T-3A-1]
			</td>
			<td>
			V (volt)
			</td>
		</tr>
		<tr>
			<td>
			29
			</td>
			<td>
			resistance
			</td>
			<td>
			Potential difference / current
			</td>
			<td>
			[ML2T-3A-2]
			</td>
			<td>
			Ω(ohm)
			</td>
		</tr>
		<tr>
			<td>
			30
			</td>
			<td>
			capacitan ce
			</td>
			<td>
			Charge / potential difference
			</td>
			<td>
			[M-1L-2T4A2]
			</td>
			<td>
			F (farad)
			</td>
		</tr>
		<tr>
			<td>
			31
			</td>
			<td>
			resistivity
			</td>
			<td>
			RA/l
			</td>
			<td>
			[ML3T-3A-2]
			</td>
			<td>
			m
			</td>
		</tr>
		<tr>
			<td>
			32
			</td>
			<td>
			Magnetic field
			</td>
			<td>
			F/[qv sinθ]
			</td>
			<td>
			[ML0T-2A-1]
			</td>
			<td>
			T (tesla)
			</td>
		</tr>
		<tr>
			<td>
			33
			</td>
			<td>
			Magnetic flux
			</td>
			<td>
			BA
			</td>
			<td>
			[ML2T-2A-1]
			</td>
			<td>
			Wb (weber)
			</td>
		</tr>
		<tr>
			<td>
			34
			</td>
			<td>
			Magnetic moment
			</td>
			<td>
			Current × area
			</td>
			<td>
			[M0L2T0A]
			</td>
			<td>
			Am2
			</td>
		</tr>
		<tr>
			<td>
			35
			</td>
			<td>
			Electric dipole moment
			</td>
			<td>
			q × 2l
			</td>
			<td>
			[M0LTA]
			</td>
			<td>
			Cm
			</td>
		</tr>
		<tr>
			<td>
			36
			</td>
			<td>
			conducta nce
			</td>
			<td>
			C = 1/R
			</td>
			<td>
			[M-1L-2T3A2]
			</td>
			<td>
			Ω-1 or mho
			</td>
		</tr>
		<tr>
			<td>
			37
			</td>
			<td>
			Mechanic al equivalent of heat
			</td>
			<td>
			W/H
			</td>
			<td>
			dimension less
			</td>
			<td>
			-
			</td>
		</tr>
		<tr>
			<td>
			38
			</td>
			<td>
			entropy
			</td>
			<td>
			Heat / temperature
			</td>
			<td>
			[ML2T-2K-1]
			</td>
			<td>
			JK-1
			</td>
		</tr>
	</tbody>
</table>

Learn the&nbsp;key concepts&nbsp;of Dimensions

Learn the key concepts of Science topic -  Dimensions

आयाम - प्रमुख अवधारणाओं को सीखें और अभ्यास करें

Hi guys, today we will be studying about the atomic structure. So let&#39;s start learning by no whether delaying.

<h2>Atomic Structure</h2>

John Dalton (1808) regarded the atom as a hard, dense and smallest indivisible particle of matter. However, the emission of negatively and positively charged particles from radioactive elements as well as from gases on the passageof electricity at very low pressures, convinced the scientists that the atom is not indivisible but consists of smaller fundamental particles. It is now fully established that an atom consists of three major fundamental particles called electrons, protons, and neutrons.

<h2>Atom</h2>

John Dalton proposed (in 1808) that the atom is the smallest indivisible particle of matter. Atomic radii are of the order of 10-8 cm or 10-10 m. It contains three subatomic particles namely electrons, protons, and neutrons.

(i) Electron - Electron was discovered as a result of the study of cathode rays by JJ Thomson. It was named by Stony. It carries a unit negative charge (1.6 × 10-19 C). Mass of the electron is 9.11 × 10-31kg and the mass of one mole of electrons is 0.55 mg.

(ii) Proton - Rutherford discovered protons on the basis of an anode ray experiment. It carries a unit positive charge (+1.6 × 10-19 C). The mass of a proton is 1.007276 u.

(iii) Neutron - Neutrons are neutral particles. It was discovered by Chadwick (1932). The mass of a neutron is 1.675 × 10- 24g or 1.008665 amu or u.

Information about some known subatomic particles:

<ul>
	<li>Positron: Discovered by Dirac (1930) and Anderson (1932).</li>
	<li>Neutrino and antineutrino: Particles having no mass and charge. Discovered by Fermi (1934)</li>
	<li>Meson: Discovered by Yukawa (1935)</li>
	<li>Antiproton: Discovered by Segre and Weigh land (1955).</li>
</ul>

<h2>J.J Thomson Model</h2>

In 1897, British physicist JJ Thomson measured the ratio of electrical charge (e) to the mass of the electron (me ) by using cathode ray tube and applying electrical and magnetic field perpendicular to each other as well as to the path of electrons. Thomson argued that the amount of deviation of the particles from their path in the presence of electrical or magnetic field may vary as follows: The e/me ratio of the proton is 9.58 × 10-4 C/g. (e/me ratio is maximum for H2 gas)

Atom is a positive sphere with a number of electrons distributed within the sphere. It is also known as the plum pudding model. It explains the neutrality of an atom. This model could not explain the results of the Rutherford scattering experiment.

<h2>Rutherford&#39;s Nuclear model of atom </h2>

It is based upon the α-particle scattering experiment. Rutherford presented that:

<ol>
	<li>Most of the atoms are empty. Most of the α- particles passed through gold foil, without undergoing any deflection from their original path.</li>
	<li>an atom possesses a highly dense, positively charged center, called nucleus of the order 10-13 cm.</li>
	<li>The entire mass of the atom is concentrated inside the nucleus.</li>
	<li>electrons revolve around the nucleus in circular orbits.</li>
	<li>electrons and the nucleus are held together by electrostatic forces of attraction.</li>
</ol>

Atomic Number (Z): Atomic number of an element corresponds to the total number of protons present in the nucleus or total number of electrons present in the neutral atom.

Mass Number (A): The mass of the nucleus is due to protons and neutrons; thus they are collectively called nucleons. The total number of nucleons is termed as the mass number of the atom. Mass number of an element = Number of Protons + Number of Neutrons

<h2>Formulation of Bohr’s model of atom</h2>

Two developments played a major role in the formulation of Bohr’s model:

<ol>
	<li>Dua character of the electromagnetic radiation which means that radiation possesses wave-like (interference, diffraction, refraction, polarization, etc) and particle-like properties (black body radiations and photoelectric effect).</li>
	<li>Atomic spectra explained by the electronic energy level in atoms.</li>
</ol>

Maxwell’s Electromagnetic Wave Theory:

The energy is emitted from source continuously in the form of radiations and magnetic fields. All electromagnetic waves travel with the velocity of their propagation. An electromagnetic wave has the following characteristics:

(i) Wavelength: It is the distance between two successive crests or troughs of a wave. It is denoted by the Greek letter λ(lambda).

(ii) Frequency: It represents the number of waves which pass through a given point in one second. It is denoted by µ (nu).

(iii) Velocity (v): It is defined as the distance covered in one second by the waves. Velocity of light is 3 × 1010 cms-1 .

(iv) Wave number: It is the reciprocal of wavelength and has units cm-1. It is denoted by ṽ (nu bar).

(v) Amplitude (a): It is the height of the crest or depth of the trough of a wave.

Wavelength, frequency and velocity of any electromagnetic radiations are related to each other as: f= vλ

Electromagnetic wave theory was successful in explaining the properties of light such as interference, diffraction etc., but it could not explain: 1. Black body radiation 2. Photoelectric effect

These phenomena could be explained only if electromagnetic waves are supposed to have particle nature. Max Planck provided an explanation for the behaviour of black body and photoelectric effect.

Planck’ Quantum theory of radiation:

Planck explains the distribution of intensity of the radiation from black body as a function of frequency or wavelength at different temperatures. E= h= hc/λ where, h = Planck’s Constant = 6.63 × 10-34 Js-1  E = energy of photon or quantum = frequency of emitted radiation n is the number of quanta of a particular frequency and ET is total energy.

Photoelectric Effect: Einstein received the Nobel Prize for his work on the photoelectric effect. It is the phenomenon in which a beam of light of a certain frequency falls on the surface of metal and electrons are ejected from it. This phenomenon is known as photoelectric effect.

<h2>Bohr’s model of atom</h2>

Neils Bohr proposed his model in 1931. Bohr’s model is applicable only for one electron system like H, He+ , Li2+ etc.

Emission Spectrum of Hydrogen:

According to Bohr’s theory, when an electron jumps from ground state to excited state, it emits a radiation of definite frequency (or wavelength) corresponding to the wavelength of each photon of light emitted, a bright line appears in the spectrum.

Limitations of Bohr’s Theory:

<ol>
	<li>It is unable to explain the spectrum of atoms other than hydrogen-like doublets or multielectron atoms.</li>
	<li>It could not explain the ability of atoms to form molecules by chemical bonds. Hence, it could not predict the shape of molecules.</li>
	<li>It is not in accordance with the Heisenberg uncertainty principle and could not explain the concept of the dual character of matter.</li>
	<li>It is unable to explain the splitting of spectral lines in the presence of magnetic field (Zeeman effect) and electric field (Stark effect).</li>
</ol>

In this blog, we came to know about the discovery of the electron, proton and neutron and their characteristics. We studied Thomson, Rutherford, and Bohr atomic models and their formulations. We understood the nature of electromagnetic radiation and Planck’s quantum theory. We explained the photoelectric effect and described features of atomic spectra. For more such informative blogs stay connected with us.

Learn the key concepts of Atomic sturcture

Learn the key concepts of Science topic -  Atomic structure

सामान्य विज्ञान - परमाणु संरचना की प्रमुख अवधारणाओं को जानें

Today we will be studying about Blood and its Classification, Blood Groups, Cardiovascular system, Types of BP. Blood is essential to life, so let&#39;s learn about it deeply.

Blood is a special connective tissue consisting of a dense fluid matrix, plasma, and formed elements. It is Alkaline in nature. It transports oxygen and nutrients to the lungs and tissue. Blood carries cells and antibodies that fight infection. It brings waste products to the kidneys and liver, which filter and clean the blood. It regulates body temperature. The major two elements of the blood is • Plasma • Blood corpuscles/ formed elements.

<h2>Classification of blood</h2>

<ol>
	<li>Plasma (55%)</li>
	<li>Blood corpuscles (45%)</li>
</ol>

Elements of plasma: 1. Water (92%) 2. Solid substance (8%) 3. Gaseous substance Co2 , O2

Elements of solid substances: 1. Organic Substance 2. Inorganic Substances (Na+ , K+ , Ca+ , Mg + Fe + , HCO3 + , Cl- , SO-4 )

Elements of organic substance: 

<ul>
	<li>Carbohydrates: (i) Glucose</li>
	<li>Protein: (i) albumin, (ii) globulin, (iii) fibrinogen, (iv) prothrombin</li>
	<li>Fat: (i) phospholipid, (ii) cholesterol, (iii) creatine</li>
	<li>NPN (non protein nitrogen) (i) urea, (ii) uric acid, (iii) creatine, (iv) creatinine</li>
</ul>

Plasma: It is a watery part of blood, yellow fluid, contains 90-92% water, protein, and other substances.

Blood corpuscles or Formed elements: The blood corpuscles are 40% - 50% part of the total blood and this part is called Haematocrit. Three types of blood corpuscles is: • Red blood corpuscles • White blood corpuscles • Platelets

Red blood corpuscles (RBC): It is also known as Erythrocytes. It does not have any nucleus in its cell whose shapes are spherical and bi-concave. RBC is produced in the spleen and liver, foetus and in bone marrow after birth. The radius of RBC is 7.2 micrometres and the circumference is 2.2 micrometres. RBC count in a male body is 14-15 gm/ 100 cc and in a female body is 12-14 gm/ 100 cc. The life of RBC is 120 days after which they are broken down in the spleen or liver. Polycythaemia refers to an increase in the number of Red Blood Cells. The deficiency of RBC is called Anaemia. The pigmented component of the haemoglobin takes part in the metabolic activities and forms a yellow coloured pigment called bilirubin.

Haemoglobin: Haemoglobin is iron-containing pigment. It is red-pigmented blood, consisting of a protein component and the iron complex of a porphyria derivative. It transfers oxygen in blood from the lungs to tissues.

White blood corpuscles (WBC): WBC is also known as leukocytes. Nucleus is present in its cells that is why it is colourless. Per cubic millimetres, there are 5,000 – 9,000 WBC present in the human blood. The ratio of WBC to RBC is 1 : 700. It can survive only for 3-4 days. WBC mainly protects the body’s immune systems.

Platelets: It is also called Thrombocytes, which are formed in the bone marrow. These are only found in the blood of Human beings and mammals in which the nucleus is absent. Blood normally contains 1,50000 to 3,50000 mm-3 platelets in human beings. It helps in blood clotting.

<h2>Blood groups of Human beings</h2>

Researcher Karl Landsteiner and his colleagues detected and observed that the blood in all human beings are not the same but are different.

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:14px">
	<tbody>
		<tr>
			<td>
			Blood

			Group
			</td>
			<td>
			Antigen (in RBC)
			</td>
			<td>
			Antibody (in

			plasma)
			</td>
		</tr>
		<tr>
			<td>
			A
			</td>
			<td>
			Only A
			</td>
			<td>
			Only B
			</td>
		</tr>
		<tr>
			<td>
			B
			</td>
			<td>
			Only B
			</td>
			<td>
			Only A
			</td>
		</tr>
		<tr>
			<td>
			AB
			</td>
			<td>
			Both A and B
			</td>
			<td>
			Absent
			</td>
		</tr>
		<tr>
			<td>
			O
			</td>
			<td>
			Absent
			</td>
			<td>
			Both a and B
			</td>
		</tr>
	</tbody>
</table>

RH factor: You must have seen at times that blood groups are often followed with a + or - sign. This indicates the presence or absence of Rh factor. In 1940 Landsteiner and Wiener discovered another type of antigen present in human blood. This antigen was extracted from a monkey namely Rhesus is called Rh-factor. Blood possessing the Rh factor is called Rh positive and lack of Rh factor is called Rh negative. Possible blood groups of offspring from parents of various blood groups:

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:28px">
	<tbody>
		<tr>
			<td>
			Blood Groups of

			parents
			</td>
			<td>
			Possible
			</td>
			<td>
			Impossible
			</td>
		</tr>
		<tr>
			<td>
			O × O
			</td>
			<td>
			O
			</td>
			<td>
			A, B, AB
			</td>
		</tr>
		<tr>
			<td>
			O × A
			</td>
			<td>
			O, A
			</td>
			<td>
			B, AB
			</td>
		</tr>
		<tr>
			<td>
			O × B
			</td>
			<td>
			O, B
			</td>
			<td>
			A, AB
			</td>
		</tr>
		<tr>
			<td>
			O × AB
			</td>
			<td>
			A, B
			</td>
			<td>
			O, AB
			</td>
		</tr>
		<tr>
			<td>
			A × A
			</td>
			<td>
			A, O
			</td>
			<td>
			B, AB
			</td>
		</tr>
		<tr>
			<td>
			A × B
			</td>
			<td>
			A, B, O, AB
			</td>
			<td>
			-
			</td>
		</tr>
		<tr>
			<td>
			A × AB
			</td>
			<td>
			A, B, AB
			</td>
			<td>
			O
			</td>
		</tr>
		<tr>
			<td>
			B × B
			</td>
			<td>
			B, O
			</td>
			<td>
			A, AB
			</td>
		</tr>
		<tr>
			<td>
			B × AB
			</td>
			<td>
			A, B, AB
			</td>
			<td>
			O
			</td>
		</tr>
		<tr>
			<td>
			AB × AB
			</td>
			<td>
			A, B, AB
			</td>
			<td>
			O
			</td>
		</tr>
	</tbody>
</table>

Lymph:

<ul>
	<li>It is worked as a middle man between blood and tissue</li>
	<li>Lymph = plasma + WBC</li>
	<li>Spleen produces Lymph at the same time it acts as the graveyard of lymph.</li>
	<li>It is a modified fluid, containing cells like lymphocytes and monocytes, salts, and small amounts of protein.</li>
	<li>It also helps in the renewal of ECF or ExtraCellular Fluid.</li>
</ul>

13 factors are responsible for blood coagulation: Fibrinogen, factor I; Prothrombin, factor II; Thromboplastin, factor III; Calcium Ion, factor IV; Labile factor, factor V; Acceleration, factor VI; Stable factor, factor VII; Antihemophilic factor, factor VIII; Christmas factor, factor IX; Stuart factor, factor X; Plasma Thromboplastin antecedent, factor XI; Hageman factor, factor XII; Fibrin stabilizing factor, factor XIII

<h2>Blood clotting system </h2>

<ul>
	<li>Sodium citrate is the anticoagulant used during blood collection and blood bank. </li>
	<li>In the &#39;O&#39; blood group there are no agglutinogens on the surface of the red blood cells but alpha and beta agglutinin are found in plasma.</li>
	<li>ABO Blood group is rare and it is known as Bombay Blood Group.</li>
</ul>

<h2>Cardiovascular system</h2>

The cardiovascular system is the system responsible for delivering blood to different parts of the body. It consists of the following organs and tissues: Heart, Artery, Vein, Capillaries

Two type of circulation system are:

<ul>
	<li>Systemic circulatory system- where blood circulates into cells, organ and tissue.</li>
	<li>Pulmonary circulatory system- where blood circulates between the heart and lungs.</li>
</ul>

Heart is mesodermal derived organs, is situated in the thoracic cavity, in between the two lungs, slightly tilted to the left. It is protected by a double wall membrane called pericardium. Our heart has four chambers. Two upper small chambers are called atria and two lower larger chambers are called ventricles. Interatrial septum separates left and right atria from each other and interventricular septum separates left and right ventricular. The SA (sinoatrial) node generates an electrical signal that causes the upper heart chambers (atria) to contract. The signal then passes through the AV (atrioventricular) node to the lower heart chambers (ventricles), causing them to contract, or pump. The SA node is considered the pacemaker of the heart. Our heart normally beats 70 – 75 times in a minute. (At an average of 72 times per minute).

Artery: Arteries are blood vessels that carry blood away from the heart to the rest of the body. The main artery of the systemic circulation is the aorta. It is attached to the left ventricle of the heart and carries oxygenated blood. The pulmonary artery differs from the others in that it is attached to the heart’s right ventricle and carries blood that is poor in oxygen to the lungs.

Vein: Veins carry deoxygenated blood from the body to the heart, where it can be sent to the lungs. The exception is the network of pulmonary veins, which take oxygenated blood from the lungs to the heart.

Capillaries: These tiny blood vessels have thin walls. Oxygen and nutrients from the blood can move through the walls and get into organs and tissues. The capillaries also take waste products away from your tissues. Capillaries are where oxygen and nutrients are exchanged for carbon dioxide and waste.

Cardiac Cycle: The cardiac cycle is defined as a sequence of alternating contraction and relaxation of the atria and ventricles in order to pump blood throughout the body. The cardiac cycle is essentially split into two phases, systole (the contraction phase) and diastole (the relaxation phase). They occur as the heart beats, pumping blood through a system of blood vessels that carry blood to every part of the body. Systole occurs when the heart contracts to pump blood out, and diastole occurs when the heart relaxes after contraction. Each of these is then further divided into an atrial and ventricular component. The cardiac cycle therefore proceeds in four stages:

<ul>
	<li>Atrial systole: It lasts about 0.1 seconds – both atria contract and force the blood from the atria into the ventricles.</li>
	<li>Ventricular systole: It lasts about 0.3 seconds – both ventricles contract, blood is forced to the lungs via the pulmonary trunk, and the rest of the body via the aorta.</li>
	<li>Atrial diastole: Lasting about 0.7 seconds – relaxation of the atria, during which the atria fill with blood from the large veins.</li>
	<li>Ventricular diastole: It lasts about 0.5 seconds – begins before atrial systole, allowing the ventricles to fill passively with blood from the atria.</li>
</ul>

The cardiac cycle comprises a complete relaxation and contraction of both the atria and ventricles, and lasts approximately 0.8 seconds. During a cardiac cycle, each ventricle pumps out approximately 70 ml of blood which is called stroke volume. The stroke volume multiplied by the heart rate gives the cardiac output. Cardiac output can be defined as the volume of the blood pumped out by each ventricle per minute and average 5000 ml or 5 litres. During each cardiac cycle Two prominent sounds are produced which can be easily heard through a stethoscope. The first sound of the heart lub is associated with closure of the tricuspid and bicuspid valves. The second sound dub is associated with the closure of the semilunar valves.

<h2>Different types of blood pressure</h2>

Systolic Blood Pressure:

During a heartbeat, the heart is pushing blood out into the arteries. This process is called “systole,” and that’s why it’s called the systolic blood pressure. It’s the pressure during a heartbeat and the highest pressure measured. When the reading is 120 mmHg or a little below while a person is sitting quietly at rest, the systolic blood pressure is considered normal High systolic blood pressure is usually caused by narrowing of the arteries, which makes the heart to work harder to push blood through.

Diastolic Blood Pressure:

Diastole occurs when the heart relaxes after contraction. Diastolic blood pressure is the measurement during this pause before the next heartbeat. A normal diastolic blood pressure during quiet rest is 80 mmHg or a little below, if you have high blood pressure, the diastolic number is often higher even during quiet rest.

Pulse Pressure: Pulse pressure is different between systolic and diastolic pressure. A normal pulse pressure range is between 40 and 60 mm Hg. Example: If blood pressure is 120/80 mmHg, pulse pressure would be 120 – 80 = 40

Electrocardiogram (ECG): ECG is a graphical representation of the electrical activity of the heart during a cardiac cycle. Each peak in the ECG is identified with a letter from P to T that corresponds to a specific electrical activity of the heart. P wave represents the electrical depolarisation of the atria which leads to the contraction of both the atria. The QRS complex represents the depolarisation of the ventricles which initiates the ventricular contraction. The contraction starts shortly after Q and makes the beginning of the systole. The wave represents the return of the ventricles from excited to normal state (repolarisation). The end of the T wave makes the end of systole.

Atherosclerosis: Plaque (fatty deposits) build up in your arteries is called atherosclerosis. Deposits are made up of cholesterol, fatty substances, cellular waste products, calcium and fibrin (a clotting material in the blood).

Blood is a vital fluid that circulates throughout the body. It is made up of plasma, red blood cells, white blood cells, and platelets. Blood transports oxygen and nutrients to cells and carries away waste products. It also helps to fight infection and to clot wounds. This was all about Blood. Hope you find this blog interesting. Stay with us for more such blogs.

Learn the key concepts of Science topic -  Blood

सामान्य विज्ञान - रक्त की प्रमुख अवधारणाओं को जानें

Today we will be discussing about Advanced defence research and technology. Let&#39;s explore without any further delaying.

Advanced defence research and technology gives us a critical advantage over potential adversaries, and is saving people’s lives. It can help to deliver better value for money. In addition, it can lead to a boost in the economy. Defence research and technology make the country self-sufficient in technologies needed for defence. Actively engaged in well-planned projects in the field of science and technology, also supports in saving foreign exchange as indigenisation in armament technology. The Department of Defence continues to lead the technical agenda in defence-specific technologies which provide advancement in making weapons, missiles, and other military equipment.

<h2>About DRDO</h2>

DRDO was established in 1958 by the Government of India, under the Ministry of Defence (Raksha Mantralaya). It was instituted by combining three major defence organisations namely: Defence Science Organisation (DSO), Defence Technical Development Establishment (DTDE) and Directorate of Technical Development and Production (DTDP). It undertakes research, design and development of weapons, weapon systems, equipment, materials and stores. The department also sponsors defence research work in universities and higher technical institutes in the country. And has training and educational institutions in defence science and technology and work-study.

Vision: To empower the nation with state-of-the-art indigenous Defence technologies and systems.

Mission: Design, develop and lead to the production of state of-the-art sensors, weapon systems, platforms and allied equipment for our Defence Services. Provide technological solutions to the Services to optimise combat effectiveness and to promote the well-being of the troops. Develop infrastructure and committed quality manpower and build a strong indigenous technology base for the defence systems and services of the country.

Highest Terrestrial Centre in Ladakh:

DRDO’s centre in Ladakh is at 17,600 feet above sea level at Changla near Pangong lake. The centre acts as a research unit for food, agriculture and bio-medical sciences that will benefit the soldiers deployed at high altitude. It serves as a natural cold storage unit for the preservation of natural and medicinal plants. DRDO started with just 10 different laboratories in the country and now has more than 50 labs across the nation researching in different sectors of technology and defence. With a project in 1960 on Surface-to-Air Missiles (SAM), Project Indigo was the DRDO’s first major defence project. This project was discontinued without any success.

Integrated Guided-Missile Development Programme (IGMDP): The main aim behind this innovation was to make Indian defence forces self-sufficient in the field of missile technology. It is one of Dr APJ Abdul Kalam’s major works. The missiles developed under IGMDP are Prithvi, Agni, Trishul, Akash, Nag. After the approval of IGMDP in 1983 from the Indian Government, DRDO brought together the country’s scientific community, academic institutions, R&D laboratories, industries and the three defence services to make India self-sufficient in the field of missile technology.

<h2>India’s nuclear weapon program</h2>

India’s nuclear program started in March 1944 and its three stage indigenous efforts in technology were established by Dr Homi Bhabha when he founded the nuclear research centre, the Institute of Fundamental Research. India first tested a nuclear device in 1974 (code-named “Smiling Buddha”), which is called a “peaceful nuclear explosion.” India performed further nuclear tests in 1998 (code-named “Operation Shakti”). Main Nuclear Authorities in India:

<ul>
	<li>Nuclear Command Authority (NCA)</li>
	<li>Strategic Nuclear Command</li>
	<li>Cabinet Committee on Security (CCS)</li>
	<li>National Security Advisory Board etc.</li>
</ul>

In August 1999, the Indian government released a draft of the doctrine which asserts that nuclear weapons are solely for deterrence and that India will pursue a policy of “retaliation only”. This is India’s No-First-Use Policy and Doctrine of Credible Minimum Deterrence (CMD). The document also maintains that India “will not be the first to initiate a nuclear first strike but will respond with punitive retaliation should deterrence fail” and that decisions to authorise the use of nuclear weapons would be made by the Prime Minister or his ‘designated successor(s).’

The civil leadership, in the form of the CCS (Cabinet Committee on Security), is the only body authorised to order a nuclear strike against another offending strike: In effect, it is the Prime Minister who has his finger “on the button.”

On January 4, 2003, the Cabinet Committee on Security (CCS) constituted the Nuclear Command Authority (NCA). NCA has two councils: Executive Council and Political Council. The Executive Council is chaired by the National Security Advisor (NSA) while the Political Council is chaired by the Prime Minister. The mechanism of Political Council being advised by Executive Council and letting the “nuclear button remain with PM” was implemented to ensure that Indian nukes remain firmly in civilian control and that there exists a sophisticated Command and Control (C2) mechanism to prevent their accidental or unauthorised use.

Strategic Nuclear Command, forms part of India’s Nuclear Command Authority (NCA). India’s Strategic Nuclear Command was formally established in 2003. It is responsible for executing all aspects of India’s nuclear policy.

The National Security Council (NSC) of India is the apex agency looking into the country’s political, economic, energy and strategic security concerns. NSC has roles beyond nuclear deterrence. The chief executive is the National Security Adviser. The three-tiered structure of the NSC comprises the Strategic Policy Group, the National Security Advisory Board and a Secretariat represented by the Joint Intelligence Committee (JIC).

What is the Nuclear Triad?

Nuclear Triad is a term used to denote a nation that has the capabilities of a nuclear strike from land, air and water. India has tested its abilities in land, air and sea, but operational missiles are not there about the sea.

<ul>
	<li>From Land: Ballistic missiles with a nuclear warhead in the Prithvi and Agni Series.</li>
	<li>From Air: Nuclear bombs from Dassault Mirage 2000s and SEPECAT Jaguars. (Free-falling and un-guided method).</li>
	<li>From Sea: Submarines: Sagarika K-15 missile in Arihant Submarine; Ship: Dhanush missile from ships like INS Subhadra or INS Rajput.</li>
</ul>

Hope you found this blog interesting and for more stay blogs stay connected with us.

Learn the key concepts of&nbsp;Defence Research &amp; Technology (DRDO, Nuclear &nbsp;Weapon Programme)

Learn the key concepts of Science topic -  Defence Research & Technology (DRDO, Nuclear Weapon Programme)

सामान्य विज्ञान - रक्षा अनुसंधान एवं प्रौद्योगिकी (डीआरडीओ, परमाणु हथियार कार्यक्रम) की प्रमुखअवधारणाओं को जानें

Hi learners, do you know how do we get the electricity in our houses? Also why do some objects have a higher requirement of electricity compared to others? All these questions will be answered in our present discussion of the topic electricity. Electricity or current electricity is the movement of charge / electrons through a wire. It could be direct or indirect and we shall discuss many more aspects related to it.

<h2>Electric current</h2>

If two bodies charged to different potentials are connected together by means of a conducting wire, charges begin to flow from one body to another. The charges continue to flow till the potentials of the two become equal. The flow of electric charges through a conductor constitutes an electric current. Quantitatively, electric current in a conductor across an area held perpendicular to the direction of flow of charge is defined as the amount of charge flowing across that area per unit time.

If a charge ΔQ passes through an area in time t to (t + Δt), then the current I at time is given by I = ΔQ/ Δt I = Q / t or Electric current = electric charge / time SI unit = 1 ampere 1 ampere = 1 coulomb/ 1 sec

Properties of Electric Current:

After we defined electric current, let us learn the properties of electric current. Electric current is an important quantity in electronic circuits. We have adapted electricity in our lives so much that it becomes impossible to imagine life without it. Therefore, it is important to know the properties of the electric current. We know that electric current is the result of the flow of electrons. The work done in moving the electron stream is known as electrical energy. The electrical energy can be converted into other forms of energy such as heat energy, light energy, etc. For example, in an iron box, electric energy is converted to heat energy. Likewise, the electric energy in a bulb is converted into light energy.

There are two types of electric current known as alternating current (AC) and direct current (DC). The direct current can flow only in one direction, whereas the alternating direction flows in two directions. Direct current is seldom used as a primary energy source in industries. It is mostly used in low voltage applications such as charging batteries, aircraft applications, etc. Alternating current is used to operate appliances for both household and industrial and commercial use. The electric current is measured in Ampere. One ampere of current represents one coulomb of electric charge moving past a specific point in one second.

<h2>Ohm&#39;s Law</h2>

Ohm’s law states the relationship between electric current and potential difference. The current that flows through most conductors is directly proportional to the voltage applied to it. Georg Simon Ohm, a German physicist was the first to verify Ohm’s law experimentally.

Ohm’s law states that the current flowing through a conductor is directly proportional to the voltage across it, provided all physical conditions and temperature remain constant.

Mathematically: I ∝ R or R ∝ V⇒ V = IR ⇒R = V/ I, SI unit = Ω (ohm)

Factors affecting the Resistance:

1. Length: The resistance R of a conductor is directly proportional to its length i.e. R ∝ l

2. Area of cross section: The resistance R of a uniform conductor is inversely proportional to its area of cross section A i.e. R ∝ 1/ A

3. Nature of the material: The resistance of a conductor also depends on the nature of its material. Combining the above factors, we get R ∝ A ⇒ R =ρ 1/A Where ρ is the constant of proportionality called resistivity or specific resistance of the material of the conductor. It depends on the nature of the material of the conductor and on the physical conditions like temperature and pressure, but it is independent of its size or shape. 

<h2>Resistivity or specific resistance</h2>

If in the above equation, we take L = 1 unit, and A = 1 square unit, then R = ρ. Resistivity of a material may be defined as the resistance of a conductor of that material, having unit length and unit area of cross section. SI unit = Ωm (ohm metre) Effect of temperature of the conductor: If the temperature of the conductor connected in the circuit increases, its resistance increases.

This was all about Electricity, electic current, Ohm’s Law, Resistivity and in next blog we will be discussing combinations of resistance and heating effect of current.

Learn the key concepts of Electricity

Learn the key concepts of Science topic -  electricity

सामान्य विज्ञान - बिजली की प्रमुख अवधारणाओं को जानें

Hi guys, in present blog we will deal with Biomolecules. So, lets start and explore deeply.

Biomolecules are the organic compounds that form the basis of life, i.e. they build up the living system and are responsible for their growth and maintenance. The sequence that relates biomolecules to living organisms is:

Biomolecules → Organelles Cells → Tissues → Organs Organ systems →Living organism

In this lesson, we would understand and learn about these biomolecules in detail.

<h2>Carbohydrates </h2>

Optically active polyhydroxy aldehydes (aldoses) or ketones (ketoses) or the compounds which produce these units on hydrolysis are known as carbohydrates. They are also called saccharides.

Classification of Carbohydrates:

(i) Reducing and Non-reducing Sugars: Based upon reducing and non-reducing properties, carbohydrates are classified as reducing and non- reducing sugars. Carbohydrates that reduce Fehling’s reagent or Tollen’s reagent are termed as reducing carbohydrates. e.g. All monosaccharides and disaccharides (except sucrose).

(ii) Sugars and Non-sugars: On the basis of taste, carbohydrates are classified as sugars and non-sugars. The monosaccharides and oligosaccharides having a sweet taste are collectively known as sugars.

(iii) Monosaccharides, Oligosaccharides and Polysaccharides: Depending upon the number of simple molecules produced upon hydrolysis, carbohydrates are classified as, monosaccharides, oligosaccharides and polysaccharides:

(a) Monosaccharides:

These cannot be hydrolysed further to simplermolecules and subdivided into tetroses, pentoses or hexoses depending upon the number of carbon atoms. These are also called homopolysaccharides.

<ul>
	<li>Aldotetroses: Erythrose, Threose</li>
	<li>Aldopentoses: Xylose, Ribose</li>
	<li>Aldohexoses: Glucose, Galactose</li>
	<li>Ketohexoses: Fructose</li>
</ul>

All naturally occurring monosaccharides belong to D-series, Killiani synthesis is used to convert an aldose into the next higher aldose.

Glucose: It is also known as Dextrose. It is present in grape sugar, corn sugar and blood sugar (C6H12O6).

Manufacture of Glucose: By hydrolysis of starch with hot dil mineral acids and by hydrolysis of sucrose. Extra glucose is stored in the liver as glycogen.

(b) Oligosaccharides:

(Greek oligos = few). On hydrolysis, they generally give two to nine monosaccharides (same or different) and are further classified as disaccharides, e.g. sucrose, maltose, lactose, trisaccharides and so on. C12H22O11 is a disaccharide as it gives two monosaccharides. The bond formed between two monosaccharides is called a glycosidic bond and normally it is a (1,4) bond. Examples of Disaccharides:

1. Sucrose (C12H22O11): Sucrose is most abundant in plants and is known as cane sugar or table sugar or invert sugar as an equimolar mixture of glucose and fructose is obtained by hydrolysis of sucrose.

2. Lactose or Milk sugar : It is present in milk of mammals and is made up of one glucose and one galactose units. It is reducing sugar. Souring of milk is due to the conversion of lactose to lactic acid.

3. Maltose or Malt sugar: It is named because of its occurrence in a malted grain of Barley. Mostly found in germinating seeds and tissue where starch is broken down. It is a reducing sugar and formed by condensation of 2 glucose units.

Trisaccharides: Carbohydrates that yield three monosaccharide units on hydrolysis are called trisaccharide e.g; Raffinose (C18H32O16).

c) Polysaccharides:

These are polymers of monosaccharides. Examples are starch, cellulose, glycogen, etc.

1. Starch, (C6H10O5 ) n : Sucrose is most abundant in plants and is known as cane sugar or table sugar or invert sugar as an equimolar mixture of glucose and fructose is obtained by hydrolysis of sucrose.

<ol>
	<li>Amylose (20%) an unbranched water soluble polymer.</li>
	<li>Amylopectin (80%) a branched water insoluble polymer.</li>
</ol>

Sources of starch are potatoes, wheat, rice, maize, etc.

2. Cellulose, (C6H10O5 ) n : It is the most abundant and structural polysaccharide of plants. It is an important foodsource for some animals. It is a polymer of D( ) + b- glucose. The chief sources of cellulose are wood(contains 50% cellulose rest being lignin, resins,etc) and cotton (contains 90% cellulose rest being fats and waxes).

<h2>Amino acids</h2>

The compounds containing an amino group (-NH2 ) and carboxylic group (—COOH) are called aminoacids. General formula: R = H, alkyl, or aryl group. Except for glycine (H2N.CH2COOH), others are optically active in nature.

Classification of Amino Acids: 

(a) α,β, γ - amino acids: Depending upon the position of —NH2 on the carbon chain wrt — COOH group.

(b) Neutral Having one -NH2 and one —COOH Example: NH2 .CH2 .COOH (Glycine)

(c) Acidic Having one -NH2 and two —COOH, Example: Aspartic acid

(d) Basic Having two or more —NH2 and one —COOH, Example: lysine

Hope you learn well through this blog

Learn the key concepts of&nbsp;Biomolecules(Carbohydrates, amino acids)

General Science - Learn the key concepts of Biomolecules(Carbohydrates, amino acids)

सामान्य विज्ञान - बायोमोलेक्युलस (कार्बोहाइड्रेट, अमीनो एसिड) की प्रमुख अवधारणाओं को जानें

Hello our dear learners, we will be discussing about Cell, Tissue and Structural Organization in Animals. So let&#39;s cover this topic. Firstly know about the basic and fundamental unit of life i.e. cell.

<h2>Cell</h2>

Cell is fundamental structural and functional unit of life. Cell was discovered in 1665 by Robert Hooke. He discovered cork cell with the help of microscope. Anton Van Leeuwenhoek first saw and described living cell.

<h2>Cell Theory</h2>

In 1838, Matthias Schleiden, a German botanist and in 1839, Theodor Schwann, a British zoologist, composed cell theory. Cell theory as understood today is:

<ol>
	<li>all organisms are composed of cells and products of cells.</li>
	<li>All cells arise from preexisting cell.</li>
</ol>

<h2>Two types of cells</h2>

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:19px">
	<tbody>
		<tr>
			<td>
			Prokaryotes
			</td>
			<td>
			Eukaryotes
			</td>
		</tr>
		<tr>
			<td>
			1. Nucleus is absent
			</td>
			<td>
			1. Nucleus is present with nuclear membrane
			</td>
		</tr>
		<tr>
			<td>
			2. Membrane bound organelle are absent
			</td>
			<td>
			2. Membrane bound organelle are present
			</td>
		</tr>
		<tr>
			<td>
			3. Complexity is much simpler
			</td>
			<td>
			3. More complex in nature and structure
			</td>
		</tr>
		<tr>
			<td>
			4. Cell structure is unicellular
			</td>
			<td>
			4. Cell structure is mostly multicellular, some unicellular
			</td>
		</tr>
		<tr>
			<td>
			5. Smaller in size
			</td>
			<td>
			5. Larger in size
			</td>
		</tr>
		<tr>
			<td>
			6. Genetic material is in circular form
			</td>
			<td>
			6. Genetic material is in linear form
			</td>
		</tr>
		<tr>
			<td>
			7. Examples- Bacteria and archaebacteria
			</td>
			<td>
			7. Examples- protista, fungi, plants, animals
			</td>
		</tr>
	</tbody>
</table>

 

<h2>Organelles of Prokaryotic cells</h2>

Cell Envelope and Modifications:

Cell envelope of prokaryotic cells have 3 layers:

<ol>
	<li>Glycocalyx- tough layer called capsule.</li>
	<li>Cell wall- It determines shape and structure. It provides support and prevents cells from bursting.</li>
	<li>Plasma membrane- Semipermeable in nature.</li>
</ol>

Ribosomes:

<ul>
	<li>15-20 nm in size</li>
	<li>2 subunit - 50S and 30S together form 70S</li>
	<li>prokaryotic ribosomes</li>
	<li>Several ribosomes attach to single mRNA form polysome or polyribosome</li>
	<li>Ribosomes are site of protein synthesis.</li>
</ul>

Inclusion bodies:

<ul>
	<li>Reserve materials in cytoplasm are stored in inclusion bodies, Membrane-less.</li>
	<li>Eg- Phosphate granules, cyanophycin granules and glycogen granules.</li>
</ul>

<h2>Organelles of Eukaryotic cells</h2>

Cell Membrane: Cell membrane is the boundary of the cell. It forms the outer limiting membrane of the animal cell. It is composed of lipid bilayer, protein and carbohydrate.

<ul>
	<li>Lipid bilayer- consist of phosphoglyceride. Arranged in membrane with polar i.e. hydrophilic part outside and nonpolar i.e. hydrophobic part outside.</li>
	<li>Protein- two types of protein are integral Or peripheral. Peripherals lie on the surface while integrals are completely or partially buried in the membrane.</li>
	<li>Carbohydrates- present on the cell surface help in cell recognition and adhesion.</li>
</ul>

Cell Wall:

<ul>
	<li>Non-living rigid structure</li>
	<li>Form outer covering of cell membrane in plants and fungi</li>
	<li>It is made up of cellulose, hemicellulose, pectins and proteins</li>
	<li>Function of cell wall is to protect cell from mechanical damage and infection.</li>
</ul>

Endoplasmic Reticulum: It is part of endomembrane system. It is continuous with nuclear membrane and divide intracellular space in two compartment luminal and extra luminal. Two type of ER are:

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:29px">
	<tbody>
		<tr>
			<td>
			RER
			</td>
			<td>
			SER
			</td>
		</tr>
		<tr>
			<td>
			1. Rough endoplasmic reticulum
			</td>
			<td>
			1. Smooth endoplasmic reticulum
			</td>
		</tr>
		<tr>
			<td>
			2. Ribosomes present on surface
			</td>
			<td>
			2. Ribosomes absent
			</td>
		</tr>
		<tr>
			<td>
			3. Help in protein synthesis and secretion
			</td>
			<td>
			3. Help in lipid synthesis
			</td>
		</tr>
	</tbody>
</table>

 

Golgi Apparatus: 

<ul>
	<li>Discovered by camillo golgi</li>
	<li>Consist of flat or disc shape sac or cisternae</li>
	<li>Arranged near nucleus has 2 surface cis and trans</li>
	<li>Function is to package the material</li>
	<li>Help in glycoprotein and glycolipids synthesis</li>
</ul>

Lysosome:

<ul>
	<li>Part of endomembrane system</li>
	<li>Formed by packaging from golgi body</li>
	<li>Contain hydrolytic enzyme which work at acidic pH, Digest carbohydrate, protein, nucleic acid etc.</li>
</ul>

Vacuoles:

Membrane bound space contain water, sap, excretory profit

Mitochondria:

<ul>
	<li>Double membrane bound organelle.</li>
	<li>Known as power house of cell, Produce energy in form of ATP.</li>
	<li>membrane divide lumen in two compartments i.e. outer and inner.</li>
	<li>Inner compartment is called Matrix and it contains single circular DNA with 70S ribosomes for protein synthesis.</li>
	<li>Mitochondria divide by fission.</li>
</ul>

Chloroplast:

<ul>
	<li>Found in all plant cell and Euglenoids.</li>
	<li>Chloroplast contain chlorophyll.</li>
	<li>Chromoplast contain carotenoids.</li>
	<li>Leucoplast are colourless and store nutrients.</li>
</ul>

Nucleus:

<ul>
	<li>Discovered by Robert Brown in 1831.</li>
	<li>Nucleus is a double membrane organelle with perinuclear space between two membrane.</li>
	<li>Matrix of the nucleus is called nucleoplasm and it contains a spherical nucleolus.</li>
	<li>Nucleus stores all the genetic information of a cell.</li>
</ul>

<h2>Tissue</h2>

Animal tissue:

Group of similar cells along with intercellular substances performing specific functions are known as tissue. Animal tissue is broadly classified in 4 categories:

1. Epithelial tissue: This tissue has a free surface which faces either body fluid or the outside environment. 

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:24px">
	<tbody>
		<tr>
			<td>
			Simple epithelium
			</td>
			<td>
			Compound epithelium
			</td>
		</tr>
		<tr>
			<td>
			Composed of single layer of cell form lining of body cavity
			</td>
			<td>
			It is multilayered and help in providing protection against stress
			</td>
		</tr>
		<tr>
			<td>
			Eg. ducts and tubes
			</td>
			<td>
			Eg. Dry surface of skin, moist surface of buccal

			cavity
			</td>
		</tr>
	</tbody>
</table>

2. Connective tissue: This tissue provides support and linking to other tissue. Eg. Cartilage, bone, blood and adipose. There are 3 types of connective tissue:

A) Loose connective tissue: cell and fibres loosely arranged in semi- fluid ground substance. Mainly present beneath skin Eg. Areolar and adipose tissue.

B) Dense connective tissue: fibres and cells are densely arranged. This can be divided into two by arrangement of fibre. Dense regular tissue in which fibres are arranged in rows. Eg. Tendon and Ligament. Dense irregular tissue in which fibres are oriented differently Eg. Skin.

<h2>Specialized Connective tissue</h2>

Eg. Cartilage, bone and blood etc.

1. Neural tissue:

<ul>
	<li>Neurons are the unit of neural tissue.</li>
	<li>Rest of the neural system consists of neuroglia. It helps in protection and support of the system.</li>
	<li>Function of neural tissue is to give response in different conditions of the body.</li>
</ul>

2. Muscle Tissue:

Muscle tissue is formed of myofibrils. There are 3 types of muscle in human body:

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:27px">
	<tbody>
		<tr>
			<td>
			 
			</td>
			<td>
			Skeletal

			muscle
			</td>
			<td>
			Smooth

			muscle
			</td>
			<td>
			Cardiac

			muscle
			</td>
		</tr>
		<tr>
			<td>
			Location
			</td>
			<td>
			Attached to bone
			</td>
			<td>
			Present in viscera organ
			</td>
			<td>
			Heart
			</td>
		</tr>
		<tr>
			<td>
			Appearance
			</td>
			<td>
			Striated
			</td>
			<td>
			Non-striated
			</td>
			<td>
			Striated
			</td>
		</tr>
		<tr>
			<td>
			Nerve supply
			</td>
			<td>
			Voluntary
			</td>
			<td>
			Involuntary
			</td>
			<td>
			Involuntary
			</td>
		</tr>
		<tr>
			<td>
			Nuclei
			</td>
			<td>
			Multinucleate
			</td>
			<td>
			Uninucleate
			</td>
			<td>
			Uninucleate
			</td>
		</tr>
	</tbody>
</table>

Cells arrange in tissues, tissues in organs and organs in the organ system. Hence all the complex body functions are carried out by this arrangement.

I hope you learned well. Study hard and stay tuned for more.

Learn the key concepts of&nbsp;Cell, Tissue and Structural Organization in Animals

Learn the key concepts of Science topic -  Cell, Tissue and Structural Organization in Animals

सामान्य विज्ञान - जानवरों में कोशिका, ऊतक और संरचनात्मक संगठन की प्रमुख अवधारणाओं को जानें

To complete your tasks, you will require this energy. Humans obtain energy from food, which contains this energy in the form of chemical energy. Your body absorbs and burns this energy from food to fuel your body so that you can run around and have fun. So, let&#39;s talk about energy today in this blog.

<h2>Energy</h2>

The classical definition of energy is a system to perform work, but because energy exists in so many forms, it is difficult to find single comprehensive definition. In a nutshell, energy is a system’s ability to make things happen. Renewable energy was historically the first source of energy used by humans. From the use of wood as a fuel source for cooking and providing heat to the use of wind energy for transportation and later as a source of mechanical energy in first machinery, renewables played a critical role in pre industrial development. It’s difficult to say when and where the renewables/non renewables grouping was introduced, but it most likely became widely used around 1973-1975 as a result of work on energy security and sustainability. There are more than one reasons to introduce such categorization, such as “do we have sufficient energy resources?” as well as energy security. 

For example, energy derived from the fusion process could be considered practically infinite. Some energy sources, such as fossil fuels and uranium, have limited quantities and occurrence and may become depleted. For the most part, we have relied on fossil fuels such as coal, oil, and natural gas for energy. However, because this is a non-renewable energy source, it will eventually run out. Renewable energy is defined as power generated from naturally replenished resources. We can promote environmental sustainability by using renewable energy sources.

<h2>Sources of energy</h2>

Sources of energy can be classified into:

<ul>
	<li>Renewable Sources</li>
	<li>Non-renewable Sources</li>
</ul>

A Renewable source is a natural resource that has no negative impact on the environment. Renewable energy sources are abundant in nature and are long-lasting. These energy resources can be replenished naturally and are non hazardous to the environment. Examples of renewable sources of energy are: Solar energy, Geothermal energy, Wind energy, Biomass, Hydropower, Tidal energy

Non-renewable energy sources harm the environment and have a finite supply. Non-renewable resources can be extracted from the earth, but they will deplete over time. Examples of non-renewable sources of energy are: Natural gas, Coal, Petroleum, Nuclear energy, Hydrocarbon gas liquids

<h2>Natural sources of energy</h2>

The natural resources around us provide a variety of energy sources. It was wood during the Stone Age. We had coal during the iron age. We now have fossil fuels such as petroleum and natural gas. So, how do we select energy sources? Good energy sources should have the following characteristics: • Maximum heat production per unit volume/mass used

<ul>
	<li>Ease of transport</li>
	<li>Low pollution</li>
	<li>Economical</li>
</ul>

<h2>Renewable source of energy</h2>

Solar Energy: Sunlight can be converted into electrical energy by a photovoltaic cell. They are typically housed in aluminium frames known as solar panels. They can be incorporated into a building’s cladding, roof tiles, or glazing. This is a completely free and limitless source of energy. Its effectiveness, however, is determined by the number of hours of daylight, cloud cover, and poor weather.

Wind Energy: Wind turbines convert wind energy into electrical energy. Because wind power is an intermittent source of energy, wind farm locations must be carefully selected to generate power effectively. They have a significant visual impact on the landscape, and residents frequently oppose plans to install them.

Hydroelectric Energy: Using turbines and other devices, hydroelectric energy generates electricity from flowing water. It is renewable and can be produced by rivers or by man made installations.Although hydropower is the largest renewable energy source for electricity in the United States, wind energy is expected to overtake it soon. Water—typically fast-moving water in a large river or rapidly descending water from a high point—is used in hydropower, which converts the force of that water into electricity by spinning the turbine blades of a generator.

Wave Energy: The ocean&#39;s energy is used to power turbines that generate electricity. Tidal power is generated by tidal waters flowing through tidal barrages in estuaries, whereas wave power is generated by surface wave energy. 

Tidal Energy: A tidal estuary is a body of water that is partially enclosed. They have one or more rivers or streams that flow into them and connect to the open sea. Although wave and tidal power are renewable energy sources, there are concerns that tidal power generation will harm marine and bird life in river estuaries.

Geothermal Energy: Because the earth’s core is hot, we can use geothermal energy to generate electricity or as a renewable heat source. This heat can be found just a few kilometers beneath the earth’s surface. BIomass Energy: Crops, waste wood, and trees are all examples of biomass, which is organic material derived from plants and animals. When biomass is burned, the chemical energy is released as heat, which can then be converted into electricity using a steam turbine.

<h2>Non- renewables energy sources</h2>

Fossil Fuels: Fossil fuels cannot be replenished. This means that they will eventually run out, which is why the cost of energy is rising. Fossil fuels encompass coal, oil, and natural gas. They are burned to generate electricity, but carbon dioxide is released in the process.

Nuclear Energy: This type of energy is derived from naturally occurring radioactive material. Typically, uranium is processed into fuel rods for nuclear reactors. Heat is produced when neutron particles collide with the fuel rods. This converts water into steam, which then powers turbines to generate electricity.

Dirty Energy: Non-renewable, or “dirty,” energy sources include fossil fuels like oil, gas, and coal. Non renewable energy sources are limited in supply and take a long time to replenish. When we fill up at the gas station, we are utilising a limited resource refined from crude oil that has existed since prehistoric times.

<h2>Renewable energy in daily life</h2>

1. Solar Power: On a smaller scale, we can use solar panels or passive solar home design to harness the sun’s rays and power the entire house. Passive solar homes are designed to welcome the sun through south-facing windows and then retain the warmth through the use of heat-storing materials such as concrete, bricks, tiles, and other materials.

2. Geothermal Heat Pumps: Geothermal technology is a fresh take on an old process—the coils at the back of your refrigerator act as a mini heat pump, removing heat from the interior to keep foods fresh and cool. Geothermal or geo-exchange pumps in homes use the constant temperature of the earth (a few feet below the surface) to cool and warm homes in the summer and winter—and even to heat water.

3. Small Wind Systems: Small wind turbines are regularly used by boats, ranchers, and even cell phone companies. Dealers now help homeowners site, install, and maintain wind turbines, though some install turbines themselves. A wind turbine may reduce your reliance on the electrical grid, depending on your electricity needs, wind speeds, and zoning rules in your area.

4. Selling the Energy You Collect: Wind and solar energy– powered homes can operate independently or be linked to the larger electrical grid via their power provider.

Most states allow homeowners to pay only the difference between the grid-supplied electricity consumed and what they have produced, a process known as net metering. If you generate more electricity than you consume, your provider may pay you the retail price for it.

Renewable Energy and You:

Advocating for renewables or implementing them in your home can hasten the transition to a clean energy future. Even if you are unable to install solar panels, you may be able to choose electricity generated by a clean energy source. If your utility does not provide renewable energy, you can purchase renewable energy certificates to offset your use.

This was all about energy. Hope you understood everything. Study hard and stay tuned for more such informative blogs.

Learn the key concepts of Energy.&nbsp;

Learn the key concepts of Science topic -  Energy

सामान्य विज्ञान - ऊर्जा की प्रमुख अवधारणाओं को जानें

Hi guys, let&#39;s talk about Heating effect of current. Let&#39;s first understand about the combination of resistance internak resistance of a cell. 

<h2>Combination of resistance</h2>

Resistors in Series: A circuit is said to be connected in series when the same number of current flows through the resistors. Resistors in series combination, For the circuit, the total resistance is given as: R (total) = R1 + R2 + ….. + Rn

Resistors in Parallel: A circuit is said to be connected in parallel when the voltage is the same across the resistors. If ‘n’ number of resistors connected in parallel. The following relation gives the total resistance here: 1/R(total) = 1/R1 + 1/R2+ 1/R3.......1/Rn

The sum of reciprocals of resistance of an individual resistor is the total reciprocal resistance of the system.

<h2>Internal resistance of a cell formula</h2>

The electromotive force (EMF) is an unfamiliar concept for most of the students. These things are closely linked to the more familiar concept that is voltage. It will also introduce the concept of the Internal Resistance of a battery. The electromotive force is defined as the potential difference which is across the terminals of the battery, that is we can say when no current is flowing through it. This is said to not seem like this as it would make a difference but we can say that every battery has Internal Resistance.

Definition of Internal Resistance: 

Internal resistance is a measure of how much a device, such as a battery or a circuit, resists the flow of electrical current through it. Internal Resistance Formula is a mathematical equation that can be used to calculate the resistance of an object in motion. Internal Resistance is caused by heat loss, friction, and other processes which act to slow down or stop the movement. Internal Resistance Formula is often used in engineering applications when designing engines of trains, cars, trucks. It can also be applied in many other situations. In this unit, we will study what Internal Resistance Formula means, how it’s calculated, and give examples with solutions so you understand how Internal Resistance works.

Internal Resistance is Important to study in the Following Ways:

<ol>
	<li>In order to improve the efficiency of an electric motor or any other electrical device, it is important to understand how much Internal Resistance that device has and how it can be reduced.</li>
	<li>Internal Resistance is applied when you study the Internal Resistance of batteries. Internal Resistance is an important concept in electrical engineering, and it can be applied to many types of projects or experiments which involve electricity.</li>
	<li>Internal Resistance is also vital when designing engines in cars, trucks, or other large vehicles. Internal Resistance can be applied in Internal Combustion Engines (ICE) to improve the performance and fuel efficiency of the engine.</li>
</ol>

Here are two simplest ways for cell connectivity:

<ol>
	<li>Series Connection: Series connection is the connectivity of the components in a sequential array of components.</li>
	<li>Parallel Connection: Parallel connection is the connectivity of the components alongside other components.</li>
</ol>

Cells in Series Connection:

In series, cells are joined end to end so that the same current flows through each cell. In case if the cells are connected in series the emf of the battery is connected to the sum of the emf of the individual cells. Suppose we have multiple cells and they are arranged in such a way that the positive terminal of one cell is connected to the negative terminal of the another and then again the negative terminal is connected to the positive terminal and so on, then we can see that the cell is connected in series.

Equivalent EMF/Resistance of Cells in Series:

If E is the overall emf of the battery combined with n number of cells and E1 , E2 , E3 ... En are the emfs of individual cells. Then E1 + E2 + E3 + …….En 

Similarly, if r1 , r2 , r3 , r n are the internal resistances of individual cells, then the internal resistance of the battery will be equal to the sum of the internal resistance of the individual cells i.e. r = r1 + r2 + r3 + r n

Cells in Parallel Connection: 

Cells are in parallel combination if the current is divided among various cells. In a parallel combination, all the positive terminals are connected together and all the negative terminals are connected together.

Equivalent EMF/Resistance of Cells in Parallel:

If emf of each cell is identical, then the emf of the battery combined with n numbers of cells connected in parallel is equal to the emf of each cell. The resultant internal resistance of the combination is: Equivalent EMF/Resistance of Cells in Series and Parallel: Assume the emf of each cell is E and internal resistance of each cell is r. As n number of cells are connected in each series, the emf of each series, as well as the battery, will be nE. The equivalent resistance of the series is nr. As, the number of series connected in parallel equivalent internal resistance of that series and parallel battery is nr/m.

<h2>Heating effect of electric current</h2>

The heating effect of electric current is widely used in our day-to-day life. The electric iron, kettle, toaster, heater, etc. are used as alternatives to the conventional methods of cooking and laundry. The same is used in electric bulbs which is the alternative of conventional lamps. These devices have revolutionized the world over the years. In this section, we will discuss the concept of the heating effect of electric current and its applications. The heating effect of current was studied experimentally by Joule in 1941. After doing his experiments Joule came to the conclusion that the heat produced in a conductor is directly proportional to the product of square of current (I2 ), resistance of the conductor (R) and the time (t) for which current is passed. Thus, H∝ I2RT

Electric Power: It is the rate at which work is done or energy is transformed in an electrical circuit. Simply put, it is a measure of how much energy is used in a span of time. Electrical energy can be either kinetic energy or potential energy. In most of the cases, potential energy is considered, which is the energy stored due to the relative positions of charged particles or electric fields. Electrical power is denoted by P and measured using Watt.

SI Unit: watt (W) or joule per second To calculate power, the most simple equation is work done divided by time.

(1) P = W/t Where, W is work done, t is time. The above expression is used mostly for mechanical power. For electric power, another equation is used, when we calculate work through the amount of charge and the potential difference through which the charge is moving.

(2) W = qV Where q = total charge used and V = voltage When we substitute (1) in (2), we understand that power is now the charge multiplied by the voltage divided by the time.

(3) P = qV/t Additionally, we know that current is the charge per second that passes through the circuit at any given time.

(4) q = It Where q = total charge and I = current (ampere) Now, when we substitute (4) in (3), we understand that power is actually the current multiplied by time multiplied by voltage, divided by time. In this case, time gets cancelled from the numerator and denominator, to give us the final equation, which is P = IV. Where, P is the power, V or voltage is the potential difference in the circuit, and I is the electric current. Power can also be written as: P = V2/R or I2R Where, V is the voltage, R is the resistance, and I is the electric current.

These can be obtained when we apply the Ohms law, which says that electric current is proportional to voltage and inversely proportional to resistance. In a series circuit, all components are connected end-to-end, forming a single path for current flow. In a parallel circuit, all components are connected across.

This was all about heating effect of current. Stay with us and solve all your queries.

Learn the key concepts of Heating effect of current

Learn the key concepts of Science topic - Heating effect of current

सामान्य विज्ञान - धारा के तापीय प्रभाव की प्रमुख अवधारणाओं को जानें

In our earlier blog, we talked about biomolecules like carbohydrates and amino acids. in our today&#39;s blog we will be taking our earlier discussion further and study about more Biomolecules that are Proteins, Enzymes, Vitamins, Nucleic Acids, Polymers. 

<h2>Proteins</h2>

They are linear polymers of a-amino acids.

Structure of Proteins:

(a) Primary structure: It simply reveals the sequence of amino acids.

(b) Secondary structure: Francis Crick and James Watson described the structure of DNA double helix in 1953. α-helix structure maintained by hydrogen bonds or β-pleated sheet structure when R is a small group.

(c) Tertiary structure: The folding and superimposition of polypeptide chains forms a compact globular shape, termed a tertiary structure. It is stabilized by covalent, ionic, hydrogen and disulphide bonds.

Denaturation of Proteins:

The process that changes the three-dimensional Structure of native proteins is called denaturation of proteins. It can be caused by change in pH, addition of electrolyte, heating or addition of solvent like water, alcohol or acetone.

<h2>Enzymes</h2>

Enzymes constitute a group of complex proteinoid organic compounds, produced by living organisms which catalyse the chemical reaction. Non-proteinous components enhance the activity of certain enzymes and are known as co-enzymes. These include metal ions like Mn+2, Mg+2, K+ , Na+ , Zn+2, Co+2, etc., heterocyclic ring systems (pyrrole, purine, pyridine, etc.), a sugar residue, phosphoric acid and residue of vitamins like thiamine, riboflavin etc. Endoenzyme acts in the same cell in which it is synthesised, while exo-enzyme acts outside the cell in which it is synthesised.

<h2>Vitamins</h2>

The organic compounds other than carbohydrates, proteins and fats which are required by body to maintain normal health, growth and nutrition are called vitamins. The vitamins are complex organic molecules. They are represented by letters such as A, B, C, D, E, K.

Vitamins are broadly classified into two types,

<ol>
	<li>Water-soluble vitamins and</li>
	<li>Fat-soluble vitamins.</li>
</ol>

Vitamins A, D, E and K are fat-soluble whereas vitamins B and C are water-soluble. Vitamin H is neither fat-soluble nor water-soluble. 

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:17px">
	<tbody>
		<tr>
			<td>
			Vitamin
			</td>
			<td>
			Deficiency
			</td>
		</tr>
		<tr>
			<td>
			A (Carotenoids or Axerophytol or retinol)
			</td>
			<td>
			Night blindness, Xerophthalmia (cornea becomes opaque), drying of skin
			</td>
		</tr>
		<tr>
			<td>
			B1 (Thiamine)
			</td>
			<td>
			Beriberi, loss of appetite.
			</td>
		</tr>
		<tr>
			<td>
			B2 (Riboflavin)
			</td>
			<td>
			Cracked lips, sore tongue and skin disorders.
			</td>
		</tr>
		<tr>
			<td>
			B6 (Pyridoxine)
			</td>
			<td>
			Nervous disturbances and convulsions
			</td>
		</tr>
		<tr>
			<td>
			B12

			(Cyanocobalamin)
			</td>
			<td>
			A serious type of anaemia. (pernicious anaemia)
			</td>
		</tr>
		<tr>
			<td>
			C (Ascorbic Acid)
			</td>
			<td>
			Scurvy, dental caries, pyorrhea, anaemia.
			</td>
		</tr>
		<tr>
			<td>
			D (Ergocalciferol)
			</td>
			<td>
			Infantile rickets, deformation of bones and teeth.
			</td>
		</tr>
		<tr>
			<td>
			E (Tocopherol)
			</td>
			<td>
			Loss of sexual power and degeneration of muscle fibers in animals.
			</td>
		</tr>
		<tr>
			<td>
			K (phylloquinone)
			</td>
			<td>
			Tendency to hemorrhage and impaired clotting of blood.
			</td>
		</tr>
	</tbody>
</table>

<h2>Nucleic Acids</h2>

Important Terms of Nucleic Acids:

(i) Nitrogenous base: Derived from purines having two rings in their structure. e.g. Adenine (A) and Guanine (G) and derived from pyrimidines having one ring in their structure e.g. Thymine (T), Uracil (U) and Cytosine (C). Two H–bonds are present between A and T (A = T) while three H-bonds are present between C and G (C ≡ G).

(ii) Pentose sugar: It is either ribose or deoxyribose (not having oxygen at C2)

(iii) Nucleoside: Ribose–/deoxyribose + one base unit from A, G, C, Tor U.

(iv) Nucleotides: Nucleotides consist of 5-carbon sugar + nitrogenousbase +1, 3-phosphate groups.

(v) Ribonucleotide: Phosphate unit + Ribose + one base unit from A, G, C, or U.

(vi) Deoxyribonucleotide: Phosphate unit + Deoxyribose + one base from A, G, C or T.

DNA and RNA:

Nucleic acid is a polynucleotide, present in the living cells or bacterial cells having no nucleus and in viruses having no cells. These are of two types:

<ol>
	<li>DNA: Deoxyribonucleic acid. DNA + H2O ⇒ Phosphoric acid + deoxyribose + A, G, C, T</li>
	<li>RNA: Ribonucleic acid. RNA + H2O ⇒ Phosphoric acid + Ribose + A, G, C, U</li>
</ol>

<h2>Polymers</h2>

The word polymer has a Greek origin, which means many units (parts). Polymer is defined as a chemical substance of a high molecular mass formed by the combination of a large number of simple molecules, called monomers, e.g. Polymerisation: The process by which the monomers combine with each other and transform into polymers, is known as polymerization.

Difference between Polymers and Macromolecules:

Polymers are also called macromolecules due to their large size but converse is not always true. A macromolecule may or may not contain monomer units, e.g. chlorophyll (C55H72O5N4Mg) is a macromolecule but not a polymer since there are no monomer units present. So, we can conclude that all polymers are macromolecules while all macromolecules are not polymers. Polymers are a diverse class of materials that have a wide range of properties, depending on their molecular structure, composition, and processing conditions. Polymers possess high molecular weight, low density, High strength and stiffness, Ductility and toughness, Thermal and electrical insulation, Chemical resistance, Biodegradability. These are just a few of the many properties that polymers an exhibit. The specific properties of a polymer depend on its chemical composition, molecular structure, processing conditions, and application requirements.

Name of Polymers with monomers:

Polymers are large molecules composed of repeating units known as monomers. Monomers are small molecules that can join together chemically to form long chains, which can then further interact with each other to form three dimensional structures. Polymers can be created from a wide range of monomers, such as ethylene, propylene, styrene, vinyl chloride, and many others. The properties of the resulting polymer will depend on the specific monomer(s) used, as well as the conditions under which the polymerization reaction takes place.

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:13px">
	<tbody>
		<tr>
			<td>
			Polymers
			</td>
			<td>
			 
			</td>
			<td>
			Monomers
			</td>
		</tr>
		<tr>
			<td rowspan="6">
			Polyolefins
			</td>
			<td>
			Polythene
			</td>
			<td>
			Ethylene or ethene
			</td>
		</tr>
		<tr>
			<td>
			Polystyrene
			</td>
			<td>
			Styrene
			</td>
		</tr>
		<tr>
			<td>
			Polyvinyl Chloride (PVC)
			</td>
			<td>
			Chloroethene (vinyl chloride)
			</td>
		</tr>
		<tr>
			<td>
			Polypropyle ne (PP) (Ziegler- Natta catalyst)
			</td>
			<td>
			Propylene
			</td>
		</tr>
		<tr>
			<td>
			Polytetraflu oroethylene (Teflon)
			</td>
			<td>
			Tetrafluoroethene
			</td>
		</tr>
		<tr>
			<td>
			Polyacryloni trile (PAN)
			</td>
			<td>
			Acrylonitrile
			</td>
		</tr>
		<tr>
			<td rowspan="2">
			Polyamides
			</td>
			<td>
			Nylon-6, 6
			</td>
			<td>
			Hexamethylenediamine

			+ adipic acid
			</td>
		</tr>
		<tr>
			<td>
			Nylon-6
			</td>
			<td>
			caprolactam
			</td>
		</tr>
		<tr>
			<td rowspan="6">
			Resins
			</td>
			<td>
			Bakelite
			</td>
			<td>
			Phenol + formaldehyde
			</td>
		</tr>
		<tr>
			<td>
			Melamine - Formaldehy de resin
			</td>
			<td>
			Melamine + formaldehyde
			</td>
		</tr>
		<tr>
			<td>
			Urea- formaldehy de resin
			</td>
			<td>
			Urea + formaldehyde
			</td>
		</tr>
		<tr>
			<td>
			Natural rubber
			</td>
			<td>
			isoprene
			</td>
		</tr>
		<tr>
			<td>
			Neoprene
			</td>
			<td>
			Chloroprene
			</td>
		</tr>
		<tr>
			<td>
			Buna-N
			</td>
			<td>
			Buta-1,3-diene + acrylonitrile
			</td>
		</tr>
		<tr>
			<td rowspan="3">
			Polyesters
			</td>
			<td>
			Polymethyl methacrylate (PMMA)
			</td>
			<td>
			Methyl Methacrylate in organic peroxide
			</td>
		</tr>
		<tr>
			<td>
			Glyptal
			</td>
			<td>
			Ethylene glycol + Phthalic acid
			</td>
		</tr>
		<tr>
			<td>
			Terlene (Dacron)
			</td>
			<td>
			Ethylene glycol + Terephthalic acid
			</td>
		</tr>
	</tbody>
</table>

In this blog, we explained about the characteristics of biomolecules like proteins and nucleic acids and hormones. For more such informative blogs stay connected with us.

Learn the key concepts of&nbsp;Biomolecules (Proteins, &nbsp;Enzymes, Vitamins, Nucleic Acids, Polymers)

Learn the key concepts of Science topic -  Biomolecules

सामान्य विज्ञान - बायोमोलेक्युलस (प्रोटीन, एंजाइम, विटामिन, न्यूक्लिक एसिड, पॉलिमर) की प्रमुख अवधारणाओं को जानें

Hi guys, hope you all are doing great. Present blog will cover the following topics: Chromosomes, Genetics and Evolution. Let&#39;s dive deep and learn well.

In Biology, evolution is the change in heritable characteristics of biological populations over successive generations. These specifications are defined by Genes which are passed on to the offspring.

Genetics is the study of science which involves Genes, Genetic Variation in organisms. Genetic processes work in combination with an organism&#39;s environment and experiences to influence development and behavior.

<h2>Chromosomes</h2>

A chromosome is a long DNA molecule with part or all of the genetic material of an organism. Chromatin contain DNA and some basic protein called histone. Every chromosome has a primary constriction called centromere. Chromosome can be of different types on the basis of position of centromere.

<h2>Cell cycle</h2>

The sequence of events by which a cell duplicates its genome, synthesizes the other constituent of cell and eventually divides into two daughter cells is termed as cell cycle.

Phases of cell cycle:

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none">
	<tbody>
		<tr>
			<td>
			INTERPHASE
			</td>
			<td>
			M PHASE
			</td>
		</tr>
		<tr>
			<td>
			Resting phase during which the cell is preparing for division.
			</td>
			<td>
			The phase when the actual cell division occurs.
			</td>
		</tr>
		<tr>
			<td>
			<ul>
				<li>G1 phase</li>
				<li>S phase</li>
				<li>G2 phase</li>
			</ul>
			</td>
			<td>
			<ul>
				<li>Mitosis</li>
				<li>Meiosis</li>
			</ul>
			</td>
		</tr>
	</tbody>
</table>

M Phase:

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none">
	<tbody>
		<tr>
			<td>
			Mitosis
			</td>
			<td>
			Meosis
			</td>
		</tr>
		<tr>
			<td>
			Refers to the cell division that forms two daughter cells each with the same number and type of chromosome as the parent cell
			</td>
			<td>
			Refers to the cell division which forms four daughter cells each with half the number of chromosomes as the parent cell
			</td>
		</tr>
		<tr>
			<td>
			There is asexual type of reproduction
			</td>
			<td>
			There is sexual type of reproduction
			</td>
		</tr>
		<tr>
			<td>
			Number of chromosomes in the daughter remain the same
			</td>
			<td>
			Number of chromosomes in the daughter cells reduce by half
			</td>
		</tr>
		<tr>
			<td>
			Division take place only one time
			</td>
			<td>
			Two-time division take place
			</td>
		</tr>
		<tr>
			<td>
			Crossing over does not occur
			</td>
			<td>
			Mixing of chromosome occur
			</td>
		</tr>
		<tr>
			<td>
			Take place in somatic cell
			</td>
			<td>
			Take place in germ cell
			</td>
		</tr>
	</tbody>
</table>

Principles of inheritance and variation:

The progenies of the same parent are not identical to each other, the reason behind it is variations

<img alt="Principles of inheritance and variation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Principles of inheritance and variation.webp" style="height:150px; width:239px" />

<h2>Mendelism</h2>

Experiments performed by Mendel in genetics and description of mechanisms of hereditary processes and formulation of principles are known as Mendelism.

<ul>
	<li>(1822-1884) Mendel was born on July 22,1822 at Heinzendorf in Austria Silesian village.</li>
	<li>In 1856-57, he started his historical experiments of heredity on pealPhum sativum) plant. His experimental work continued on the pea plant till 1865 (19th century).</li>
</ul>

<ol>
	<li>He developed the technique Emasculation and Bagging for hybridization in plants.</li>
	<li>Flowers of pea plant and bisexual. In this method one is considered as male and another as female.</li>
	<li>Stamens of the plant which are used as females are removed in bud condition, this is called Emasculation.</li>
	<li>Emasculation is done to prevent self-pollination.</li>
	<li>Emasculated flowers covered by bags; this is called bagging Bagging is used to prevent undesirable cross pollination.</li>
	<li>Mature pollen grains are collected from male plant and dusted on the stigma of emasculated flower.</li>
	<li>Seeds are formed in the female flower after pollination.</li>
	<li>The plants that are obtained from these seeds are called first filial generation or F, generation according to Mendel.</li>
	<li>The plants of F, generation are self pollinated & F, generation is produced.</li>
</ol>

<h2>Monohybrid cross</h2>

When we consider the inheritance of one character at a time in a cross this is called a monohybrid cross

<img alt="Monohybrid Cross" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Monohybrid Cross.webp" style="height:150px; width:244px" />

<h2>Dihybrid cross</h2>

A cross in which study of inheritance of two pairs of contrasting traits is carried out is called a Dihybrid cross. Mendel wanted to observe the effect of one pair of heterozygous traits on another pair. Mendel selected traits for dihybrid cross for his experiment as follows.

<ol>
	<li>Color of cotyledons →Yellow (Y) & Green (y)</li>
	<li>Seed shape → Round (R) and Wrinkled (r)</li>
</ol>

Yellow and round characters are dominant and green and wrinkled are recessive characters. Mendel crossed, yellow and round seeded plants with green and wrinkled seeded plants.

<h2>Linkage and recombination</h2>

<ul>
	<li>Both terms given by Morgan.</li>
	<li>Collective inheritance of character is called linkage.</li>
	<li>Genes present on a chromosome inherited together because such genes are physically attached to the same structure.</li>
	<li>Linkage was first seen by Bateson and Punnett in Lathyrus odoratus and gave a coupling and repulsion phenomenon.</li>
	<li>Sex linkage was first discoverd by Morgan in Drosophila. He proposed the theory of linkage.</li>
</ul>

Theory of linkage:

<ol>
	<li>Linked genes are linearly located on the same chromosome.</li>
	<li>Linked genes enter together into the gametes hence only parental combinations are obtained. But linkage is not absolute i.e. linked genes could be separated during meiosis due to crossing over. Thus, a new combination of genes (non parental/ recombinant) formed.</li>
	<li>Recombination separation of linked genes and formation of new genes combination is recombination. It’s a result of crossing over.</li>
</ol>

Strength of linkage is inversely proportional to the distance between the genes. It means, if the distance between two genes is increased then strength of linkage is reduced and it proves that greater is the distance between genes, the greater is the probability of their crossing over. Morgan by his investigation on the Drosophila found two types of linkage: 1. Complete linkage 2. Incomplete linkage

Complete linkage: The complete linkage is the phenomenon in which parental combinations of characters appear together for two or more generations inherited as such. In this type of linkage genes are closely associated and tend to transmit together over the generation due to absence of crossing over.

Incomplete linkage: The linked genes are widely located in chromosomes and have chances of separation by crossing over. Genes present in the same chromosomes produce recombinant progeny besides the parental type.

<h2>Sex determination</h2>

There are different methods for sex determination in organisms like environmental, non-allosomic genetic determination, allosomic sex determination and haplodiploidy. Chromosomes are of two types:

<ol>
	<li>Autosomes or somatic chromosomes. These regulate somatic character.</li>
	<li>Allosomes or Heterosomes or Sex chromosomes.</li>
</ol>

<h2>Mutation </h2>

<ul>
	<li>Sudden heritable change in genetic material of an organism is called Mutation.</li>
	<li>Mutations are discontinuous.</li>
	<li>Frequency of mutation at present is 1 × 10-6 (1 per 1 million individuals). Mutation word was given by Hugo de Vries.</li>
	<li>De Vries studied mutations in the plant Oenothera lamarckiana (evening primrose). It is a hybrid plant.</li>
	<li>De Vries gave the mutation theory of evolution. </li>
	<li>This theory was given in support of Darwinisth because Darwin was unable to explain the source of variations.</li>
	<li>Darwin called variations as sports.</li>
</ul>

According to De Vries there are two types of variations:

(i) Continuous variations: These variations develops in every generation of an organisms, these are developed by crossing over meiosis sexual reproduction. Only minor variations are developed by crossing over.

(ii) Discontinuous variations: These variations develop by mutations suddenly appear in any generation both minor and major types of variations are developed by mutations (mostly major type).

Seth Right: Mutation was first observed by him. He observed some short-legged sheep (Ancon variety) In a population of long-legged sheep.

Morgan: Credit for the discovery of mutation is given to him. He observed some white eyed male Drosophila in a population of red eyed Drosophila.

In Drosophila eye colour is a sex-linked character. Gene of eye color is located on the X chromosome.

<h2>Genetic disorders</h2>

Thalassemia: Thalassemia is a genetic blood disorder that affects the production of hemoglobin, the protein in red blood cells that carries oxygen throughout the body. People with thalassemia have abnormal hemoglobin production, which can result in anemia, a condition where the body doesn&#39;t have enough red blood cells to carry oxygen.

Phenylketonuria: Phenylketonuria (PKU) is a genetic disorder in which the body cannot break down an amino acid called phenylalanine, which is found in many types of protein containing foods. This results in a buildup of phenylalanine and its byproducts in the body, which can cause brain damage and other serious health problems if left untreated.

Cystic Fibrosis: Cystic fibrosis (CF) is a genetic disorder that affects the lungs, pancreas, and other organs. It is caused by a mutation in a gene called CFTR, which produces a protein that regulates the movement of salt and water in and out of cells. In people with CF, this protein is not working properly, which leads to a buildup of thick, sticky mucus in the lungs, pancreas, and other organs.

Alzheimer’s Disease: Alzheimer&#39;s disease is a progressive neurological disorder that affects memory, thinking, and behavior. It is the most common cause of dementia, a group of brain disorders that affect a person&#39;s ability to function independently.

Huntington’s Chorea: It is an autosomal dominant disorder. The gene responsible for this disorder is present on chromosome.

<h2>Evolution</h2>

Origin of life: This theory was proposed by Abbe Lemaitre. According to it, the universe originated about 20 billion years ago due to a thermonuclear explosion of a dense entity. This thermonuclear explosion is called Big-bang. About 4.6 billion years ago, the origin of our solar system took place by the gaseous clouds formed due to this explosion.

<h2>Evidences of organic evolution</h2>

In support of organic evolution some important evidences are: occurrence of homologous and vestigial organs.

Paleontological evidences:

The study of fossils is known as paleontology.

<ol>
	<li>Types of Rocks (Sedimentary, Igneous, Metamorphic)</li>
	<li>Types of fossils (Unaltered, Petrified, Human teeth, Mold, Cast, Print and coprolites)</li>
</ol>

Morphological and Anatomical Evidence:

<ol>
	<li>Homology: The similarity based on common origin, similar basic plan of organization and embryonic development is called homology. Ex: forelimbs of mammals, legs of invertebrates, mouthparts of insects, radish and carrot, potato and ginger </li>
	<li>Anatomy: It is similar in organs based on similar functions. Organs which have different origin and dissimilar fundamental structure but have similar function are called analogous organs. Ex: wings of bats and birds to wings of insects, hands of man and trunk of elephant, potato and sweet potato.</li>
</ol>

Hope all your queries related to this topic are clear. Stay tuned with us.

Learn the key concepts of&nbsp;Chromosomes, Genetics and Evolution

Learn the key concepts of Science topic - Chromosomes, Genetics and Evolution

सामान्य विज्ञान - क्रोमोसोम, आनुवंशिकी और विकास की प्रमुख अवधारणाओं को जानें

Our today&#39;s blog will deal with Nuclear technology. Nuclear technology is the technology which involves the reactions in the atomic nuclei of an atom. The changes in the nucleus of atoms are normally caused by either nuclear fusion or nuclear fission and the energy released is called nuclear energy. The power that holds the nucleus together is officially called the “strong force.” Nuclear energy can be used to create electricity, but it must first be released from the atom. In the process of nuclear fission, atoms are split to release that energy while in nuclear fusion, atoms combine and again release that energy. 

<h2>History of Nuclear Technology</h2>

In early 1942 , Enrico Fermi led a group of scientists in initiating the first self-sustaining nuclear chain reaction at University of Chicago. By November 1942, they were ready for construction to begin on the world’s first nuclear reactor, which came to be known as Chicago Pile-1. When the rods were in the pile, there were fewer neutrons to fission uranium atoms. This slowed the chain reaction. When the rods were pulled out, more neutrons were available to split atoms. The chain reaction sped up. On the morning of December 2, 1942, the scientists were ready to begin a demonstration of Chicago Pile-1. Fermi ordered the control rods to be withdrawn a few inches at a time during the next several hours. Finally, the nuclear reaction became self- sustaining and Fermi and his team had successfully transformed scientific theory into technological reality. The world had entered the nuclear age. 

<h2>Nuclear energy</h2>

Nuclear energy is the energy in the nucleus, or core, of an atom. Nuclear energy can be used to create electricity, but it must first be released from the atom. When the process is repeated over and over, it is called a chain reaction. In a nuclear power plant, uranium is the material used in the fission process.

What is nuclear fuel?

Nuclear fuel is the element that is used in nuclear power plants to produce heat to power the turbines. Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission. Most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing and sustaining nuclear fission. The three most relevant fissile isotopes are uranium- 233, uranium-235 and plutonium-239. When the unstable nuclei of these atoms are hit by a slow-moving neutron, they split, creating two daughter nuclei and two or three more neutrons. These neutrons then go on to split more nuclei. This creates a self-sustaining chain reaction that is controlled in a nuclear reactor, or uncontrolled in a nuclear weapon.

Nuclear Power Plant:

A nuclear power plant is a station where all the nuclear reactions take place inside a nuclear reactor. In 1951, the first time that heat from a nuclear reactor was used to generate electricity. Nuclear power plants have a carbon footprint comparable to that of renewable energy such as solar farms and wind farms, and much lower than fossil fuels such as natural gas and brown coal. Despite some spectacular catastrophes, nuclear power plants are among the safest modes of electricity generation, comparable to solar and wind power plants.

Nuclear Reactions: 

Nuclear reactions cause changes in the nucleus of atoms which in turn leads to changes in the atom itself. Nuclear reactions convert 1 element into a completely different element. Suppose if a nucleus interacts with any other particles then separates without altering the characteristics of other nuclei then the process is called nuclear scattering rather than specifying it as a nuclear reaction. This does not imply radioactive decay. One of the most evident nuclear reactions is nuclear fusion reaction that occurs in fissionable materials producing induced nuclear fission.

Nuclear Reactions – Types:

Inelastic scattering: This process takes place when a transfer of energy occurs. It occurs above threshold energy. Et = ((A + 1)/A) × E1, where Et is called as the inelastic threshold energy and E1 is the energy of the first excited state.

Elastic Scattering: It occurs when there is energy transfer between a particle and intended nuclei. It is the most vital process for slowing down neutrons. In the case of an elastic scattering total kinetic energy of any system is conserved.

Transfer Reactions: The absorption of a particle followed by discharge of 1 or 2 particles is referred to as transfer reactions. 

Capture Reactions: When nuclei capture neutral or charged particles followed by discharge of α-rays, it is termed as capture reactions. Radioactive nuclides are produced by neutron capture reactions.

Advantages of Nuclear Energy Production:

<ol>
	<li>Nuclear energy has the least impact on the environment, as it does not pollute air.</li>
	<li>Nuclear plant does not require a very large area for setup.</li>
	<li>Nuclear energy plants do not release greenhouse gases.</li>
	<li>Once constructed and made it operative, its maintenance cost is much cheaper</li>
</ol>

Disadvantages of Nuclear Energy Production:

There are various disadvantages of Nuclear Energy Production:

<ol>
	<li>It is very expensive to set up a nuclear plant.</li>
	<li>Different types of approvals are required including government’s approval.</li>
	<li>Nuclear waste is very hazardous, as it remains radioactive for thousands of years.</li>
	<li>Though it is rare, nuclear accidents are highly fatal. For example, the Chernobyl disaster (about 30 thousand people died).</li>
</ol>

<h2>Nuclear Power in India</h2>

India is one of the largest producers of electricity in the world. The various power plants we have here in India are mentioned below:

<ol>
	<li>Rajasthan Atomic Power Station – 1973, Rajasthan</li>
	<li>(Kalpakkam) Madras Atomic Power Station – 1984, Tamil Nadu</li>
	<li>Tarapur Atomic Power Station – 1969, Maharashtra</li>
	<li>Narora Atomic Power Station- 1991, Uttar Pradesh</li>
	<li>Kakrapar Atomic Power Station – 1993, Gujarat</li>
	<li>Kaiga Nuclear Power Plant -2000, Karnataka</li>
	<li>Kudankulam Nuclear Power Plant – 2013, Tamil Nadu</li>
</ol>

IMPORTANT:- India started building nuclear power plants in ‘fleet mode’ from 2023. Under the fleet mode, a nuclear power plant is expected to be built over a period of five years from the first pour of concrete. It was for the first time that the government had approved building 10 nuclear power reactors in one go with an aim to reduce costs and speed up construction time.

Hope you liked learning interesting points about the nuclear technology. Stay connected for more.

Learn the&nbsp;key concepts&nbsp;of Nuclear technology

Learn the key concepts of Nuclear technology

Have you ever wondered about what is it that makes an ice solid whereas water a liquid though both can be reversibly interchanged with one another? There are certain properties that an ice possesses which are different from its liquid counterpart and so is the difference between water and steam. Substances (solid, liquids and gases) have certain unique characteristic properties of their own that makes them so different from each other. So, in our present blog we will be discussing about general properties of matter. 

<h2>What is matter?</h2>

Matter is described as something that has mass and occupies space. All physical structures are made up of matter, and the state or process of matter is an easily observed property of matter. Solid, Liquid, and Gas are the three basic states of matter. Properties of matter are either physical or chemical properties based on whether the properties are determined without changing the identity of a substance or not.

<h2>Physical properties of matter</h2>

<ul>
	<li>Matter is made up of tiny particles called atoms and can be represented or explained as something that takes up space. It must display both the mass and volume properties.</li>
	<li>Properties are the characteristics that enable us to differentiate one material from another. A physical property is an attribute of matter that is independent of its chemical composition.</li>
	<li>Density, color, hardness, melting and boiling points, and electrical conductivity are all examples of physical properties.</li>
</ul>

Intensive and Extensive Properties of Matter:

Both physical and chemical properties of matter are either extensive or intensive. Extensive properties including mass and volume are proportional to the amount of matter being weighed. Density and color, for example, are not affected by the amount of matter present.

Intensive properties of matter: An intensive property is a bulk property, which means it is a system’s local physical property that is independent of the system’s size or volume of material. Intensive properties are those that are independent of the amount of matter present. Pressure and temperature, for example, are intensive properties.

Extensive properties of matter: A property that is dependent on the amount of matter in a sample is known as an extensive property. Extensive properties include mass and volume. The scale of the system or the volume of matter in it determines an extensive property of the system. Extensive properties are those in which the value of a system’s property is equal to the sum of the values for the parts of the system.

Chemical Properties of Matter:

Chemical properties are characteristics that can only be measured or observed as matter transforms into a particular type of matter. Reactivity, flammability, and the ability to rust are among them. The tendency of matter to react chemically with other substances is known as reactivity. Flammability, toxicity, acidity, reactivity of various types, and heat of combustion are examples of chemical properties.

Reactivity: The tendency of matter to combine chemically with other substances is known as reactivity. Certain materials are highly reactive, whereas others are extremely inactive. Potassium, for example, is extremely reactive, even in the presence of water. A pea-sized piece of potassium reacts explosively when combined with a small volume of water.

Flammability: The tendency of matter to burn is referred to as flammability. As matter burns, it reacts with oxygen and transforms into various substances.

Toxicity: Toxicity refers to the extent to which a chemical element or a combination of chemicals may harm an organism.

Acidity: A substance’s ability to react with an acid is a chemical property. Some metals form compounds when they react with different acids. Acids react with bases to create water, which neutralizes the acid. Chemical properties are extremely helpful when it comes to distinguishing compounds.

Chemical properties, on the other hand, can only be detected when a material is in the process of being changed into another substance. 

<h2>States of matter</h2>

A state of matter is one of many possible distinct forms that matter can exist in. There are four states of matter: solid, liquid, gas and plasma. Each state has distinct properties that distinguish it from the other states, and there are phase transition processes by which matter changes from one state to another.

Properties of Solids:

When you think of a solid, you probably think of something hard or firm in some way. But solids can be flexible, deformable and malleable as well. Solids are distinguished by their tightly bound molecules. Matter in its solid state tends to be denser than when it is in its liquid state (though there are exceptions, most notably water). Solids hold their shape and have a fixed volume. One type of solid is a crystalline solid. In a crystalline solid, the molecules are arranged in a repeating pattern throughout the material. Crystals are easily identifiable by their macroscopic geometry and symmetries.

Properties of Liquids:

Liquids are made of molecules that can flow easily past each other. The water you drink, the oil you cook with and the gasoline in your car are all liquids. Unlike solids, liquids take the shape of the container. Though liquids can expand and contract at different temperatures and pressures, these changes are often small, and for most practical purposes, liquids can be assumed to have a fixed volume as well. The molecules in a liquid can flow past each other. A liquid’s propensity to be slightly “sticky” when attached to a surface is called adhesion, and the ability of liquid molecules to want to stick together (such as when a water droplet forms a ball on a leaf) is called cohesion.

In a liquid, pressure depends on depth, and because of this, submerged or partially submerged objects will feel a buoyant force due to the difference in pressure on the top and bottom of the object. Archimedes’ principle describes this effect and explains how objects float or sink in liquids. It can be summarized by the statement that “the buoyant force is equal to the weight of displaced liquid.” As such, the buoyant force depends on the density of the liquid and the size of the object. Objects that are denser than the liquid will sink, and those that are less dense will float.

Properties of Gases:

Gases contain molecules that can move easily around each other. They take the full shape and volume of their container and very easily expand and contract. Important properties of a gas include pressure, temperature and volume. In fact, these three quantities are sufficient to completely describe the macroscopic state of an ideal gas. An ideal gas is a gas in which the molecules can be approximated as point particles and in which it is assumed that they don’t interact with each other. The ideal gas law describes the behavior of many gases and is given by the formula:

PV = nRT

Where P is pressure, V is volume, n is the number of moles of a substance, R is the ideal gas constant. (R = 8.3145 J/molK) and T is temperature. An alternative formulation of this law is PV = NkT Where N is the number of molecules and k is Boltzmann’s constant ( k = 1.38065 × 10-23 J/K). (A skeptical reader can verify that nR = Nk)

Gases also exert buoyant forces on objects immersed in them. While most everyday objects are denser than the air around us, making this buoyant force not very noticeable, a helium balloon is a perfect example of this.

<h2>Mechanical properties of solid</h2>

Deforming Force: A force which produces a change in configuration of the object on applying it, is called a deforming force.

Elasticity: Elasticity is that property of the object by virtue of which it regains its original configuration after the removal of the deforming force.

Elastic Limit: Elastic limit is the upper limit of deforming force upto which, if deforming force is removed, the body regains its original form completely and beyond which if deforming force is increased the body loses its property of elasticity and gets permanently deformed.

Perfectly Elastic Bodies: Those bodies which regain their original configuration immediately and completely after the removal of deforming force are called perfectly elastic bodies. e.g., quartz and phosphor bronze etc.

Perfectly Plastic Bodies: Those bodies which do not regain its original configuration at all on the removal of deforming force are called perfectly plastic bodies, e.g., putty, wax etc.

Hope you liked the blog. Stay tuned for more.

Learn the&nbsp;key concepts&nbsp;of matter

Learn the key concepts of Science topic -  Matter

In our present blog, we would understand and learn about these states of matters in detail. To determine the properties of substances, we deal with the aggregates of molecules. These aggregations of molecules that come within the scope of human experience that constitutes are known as matter. Matter can be divided roughly into three categories: 1. Gases 2. Liquids 3. Solids

All these states arise due to competition between opposing molecular forces, that is a force of attraction which tends to hold the molecules together and the disruptive forces due to the thermal energy of molecules.

Gaseous State: Thermal energy is greater than force of attractions between molecules.

Liquid State: Thermal energy is smaller than the force of attractions between molecules.

Solid State: Thermal energy is much smaller than the force of attraction between molecules.

<h2>Matter</h2>

Anything that occupies space, has mass and can be felt by humans is known as Matter. Example: Sugar, sand, Hydrogen, oxygen etc. Matter can be differentiated based on their compositions and can be divided into two types:

<ol>
	<li>Physical Composition - Based on Intramolecular forces between molecules</li>
	<li>Chemical Composition - Based on physical and chemical properties of substance</li>
</ol>

<h2>Gaseous State</h2>

Variables that define state of a Gas:

(a) Pressure: It is denoted by P. It represents pressure exerted by the gas molecules on the wall of the container assuming negligible intermolecular force of attraction.

(b) Volume: It is denoted by V. It represents free volume available for motion. Free volume = volume of container – Actual Volume occupied by gas molecule. We consider the volume of gas is equal to the volume of the container if the actual volume of gas is negligible (valid only for ideal gases).

(c) Temperature: It is denoted by T. It is a measure of Kinetic Energy of gases.

(d) Moles: It is denoted by n. It represents the amount of gas. SI unit: moles.

Experimental Gas Laws:

It is applicable for ideal gas only. It describes the relationship between the four parameters P, V, T and n.

<ul>
	<li>Boyle’s Law:</li>
</ul>

Volume of a fixed mass of gas is inversely proportional to its pressure at constant temperature. At constant Temperature: P∝1/VP , PV = Constant This law can be represented by a plot between V and P at constant temperature. Such plots are called Isotherms.

<img alt="Boyles Law Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Boyles Law Diagram Representation.webp" style="height:150px; width:189px" />

<ul>
	<li>Charles Law:</li>
</ul>

It states that the volume of a given mass of a gas at constant pressure increase or decrease by 1/273 of its volume of 0oC for each degree rise or fall of temperature. Here, volume of a fixed mass of the gas at constant pressure is directly proportional to its temperature in Kelvin. At constant pressure: V ∝T, V1 T2 = V2 T1 . This law can be represented by a plot between V and T at constant pressure. Such plots are called Isobar.

<img alt="Charles Law Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Charles Law Diagram Representation.webp" style="height:150px; width:196px" />

<ul>
	<li>Gay-Lussac’s Law:</li>
</ul>

The pressure of a given mass of a gas at constant volume is directly proportional to temperature in Kelvin. At constant Volume: P ∝T, P / T = Constant, P1 T2 = P2 T1 This law can be represented by a plot between P and T at constant volume. Such plots are called Isochore.

<img alt="Gay Lussac Law Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Gay Lussac Law Diagram Representation.webp" style="height:150px; width:179px" />

<ul>
	<li>Avogadro’s Law:</li>
</ul>

It states that an equal number of molecules of different gases under identical conditions of temperature and pressure occupy the same volume. At constant Temperature and Pressure: V ∝N, V / N = Constant, V1n2 = V2n1 This law can be represented by a plot between V and n at constant pressure and temperature.

<img alt="" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Avogadro Law Diagram Representation.webp" style="height:150px; width:179px" />

Equation of State:

This equation describes the relationship between all four variables that define the state of a gas. PV = nRT pM = dRT Here, R is a universal gas constant and is given by R = PV / nT

SI unit: R = 0.08314 bar dm3 K-1 mol-1 , R = 8.314 J K-1 mol-1 = 0.0821 L atm K-1 mol-1 = 0.083 L bar K-1 mol-1 =1.98722 cal K-1 mol-1 

Mixture of gases:

Dalton’s Law of Partial pressures: The total pressure exerted by a mixture of non-reactive gases is equal to the sum of the partial pressures of individual gases. PTotal = P1 + P2 + ……. where, P1 , P2 = partial pressure of gas 1 and gas 2, PTotal = nTotalRT, nTotal = total amount of gases in mixture. Partial pressure for gas 1 and gas 2 is given by P1 = n1 / ntotal Ptotal X1Ptotal, X1 = mole fraction of gas 1, P2 = n1 / ntotal Ptotal X2Ptotal , X2 = mole fraction of gas 2

Average Molecular mass of gaseous mixture: Mmix = Total mass of mixture / Total no. of moles in mixture = n1M1 + n2M2 + .... / n1 + n2 + .....

<h2>Andrews Isotherm</h2>

In 1869, Thomas Andrews carried out an experiment in which P–V relations of carbon dioxide gas were measured at various temperatures. The types of isotherms obtained are shown in figure.

<img alt="Andrews Isotherm Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Andrews Isotherm Diagram Representation.webp" style="height:150px; width:192px" />

(1) At high temperatures, such as T4 , the isotherms look like those of an ideal gas.

(2) At low temperatures, the curves have altogether different appearances.

Critical Constants:

<ul>
	<li>Critical temperature (TC ): The maximum temperature at which a gas can be liquefied.</li>
	<li>Critical pressure (PC ): The minimum pressure required to cause liquefaction at the temperature TC .</li>
	<li>Critical volume (VC ): The volume occupied by one mole of a gas at critical temperature TC and critical pressure PC .</li>
</ul>

<h2>Liquid state</h2>

Properties of liquid state:

<ol>
	<li>There exists a short-range order.</li>
	<li>Close packing of molecules or atoms or ions exist to some extent in liquid state.</li>
	<li>A liquid has a definite volume but not a definite shape.</li>
	<li>The intermolecular forces are fairly strong in liquid state.</li>
</ol>

Vapour Pressure:

The Vapour pressure of a liquid at a given temperature may be defined as the pressure of the Vapour in equilibrium with the liquid at that temperature. It is a measure of the escaping tendency of molecules from the surface of the liquid. The vapour pressure of a liquid increases with the increase in temperature.

Variation of Vapour pressure with temperature can be given by Clapeyron equation:

dp/ dT = ΔvapHm /T (Vm,v - Vm,l)

where, dp/dT is the rate of change of vapour pressure with temperature, DvapHm is the molar enthalpy of vaporization of liquid, Vm,v and Vm,l are molar volumes of vapour and liquid

Boiling Point:

The temperature at which its vapour pressure is equal to the external pressure is known as Boiling point of a liquid. If pressure is equal to 1 atm or 1.01325 bar, then boiling point is known as normal boiling point.

<img alt="Boiling Point Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Boiling Point Diagram Representation.webp" style="height:150px; width:263px" />

<h2>Solid state</h2>

Solid state is a very vast topic. In this blog, we will study only about types of solids and classification of crystalline solids.

Properties of solid state:

<ol>
	<li>Solids are distinguished by their tightly bound molecules.</li>
	<li>Solids hold their shape and have a fixed volume.</li>
	<li>One type of solid is a crystalline solid In which the molecules are arranged in a repeating pattern throughout the material. Crystals are easily identifiable by their macroscopic geometry and symmetries.</li>
	<li>Another type of solid is an amorphous solid in which the molecules are not arranged in a crystal lattice at all. A polycrystalline solid is somewhere in between. It is often composed of small, single crystal structures, but without a repeating pattern.</li>
	<li>They have low compressibility and are rigid and the Intermolecular distances are also short.</li>
	<li>They have definite mass, volume and shape.</li>
</ol>

In this blog, we studied about different types of matter and their properties. We learned about Solid, Liquid and Gaseous states in this blog.

Learn the&nbsp;key concepts&nbsp;of&nbsp;States of matter

Learn the key concepts of Science topic - States of Matter

Hello our dear learners, we will be studying about Basis of ecology. So, let&#39;s dive deep and study.

The term ecology was coined and described by Ernst haeckel. The study of interactions or inter-relationships of organisms with their environment is called ecology.

<h2>Organisms and population</h2>

Organism: An organism is the smallest unit of ecological hierarchy and is the basic unit of ecological study.

Biomes: A large regional unit delimited by a specific climatic zone, having a particular major vegetation zone and its associated fauna, eg. tundra desert, temperate deciduous forest, tropical min forest, ocean etc.

On The basis of variation in mean temperature along latitude the main climatic regions are

<ol>
	<li>Tropical = 0° - 20° latitude</li>
	<li>Subtropical = 20° - 40° latitude</li>
	<li>Temperate = 40° - 60° latitude Arctic and Antarctic = 60° and above latitude.</li>
</ol>

<h2>Abiotic environmental factors</h2>

1) Temperature:

Average temperature on land varies seasonally, decreases progressively from the equator towards the poles and from plains to the mountain tops. There are, however, unique habitats such as thermal springs and deep-sea hydrothermal vents where average temperatures exceed 1000 C. A few organisms can tolerate and thrive in a wide range of temperatures (they are called eurythermal, but a vast majority of them are restricted to a narrow range of Temperatures (such organisms are called stenothermal. The levels of thermal tolerance of different species determine to a large extent their geographical distribution.

2) Water:

Next to temperature, water is the most important factor influencing the life of organisms. Organisms living in lakes and rivers face many water-related problems. For aquatic organisms the quality chemical composition of water becomes important. The salt concentration (measured as salinity in parts per thousand), is less than 5 percent in inland waters, 30-35 per cent in the sea and more than 100 per cent in some hypenaire lagoons. Some organisms are tolerant of a wide range of salinities(euryhaline)but others are restricted to a narrow range (stenohaline). Many freshwater animals cannot live for long in seawater and vice versa because of the osmotic problems they would face.

Stratification in lake:

<img alt="Stratification in lake Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Stratification in lake Diagram Representation.webp" style="height:150px; width:238px" />

In deep lake, zonation or stratification may be according to the need of light.

<h2>Responses to abiotic factors</h2>

On the basis of response to environmental factors organisms are of two types-Regulator and Conformers.

Regulators: Some organisms are able to maintain homeostasis by physiological (sometimes behavioural also) means which ensure constant body temperature, constant osmotic concentration, etc. All birds and mammals, and a very few lower vertebrate and invertebrate species are also capable of thermoregulation and osmoregulation.

Conformers: Organisms which cannot maintain a constant internal environment with the changing external environment are called conformers. 

<img alt="Response to Abiotic Factors Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Response to Abiotic Factors Diagram Representation.webp" style="height:150px; width:220px" />

Population: A group of individuals (members) of the same species living in an area (geographical/political) constitute a population or local population or deme. eg. Humans inhabiting hills, plains etc.

Population Attributes:

<ol>
	<li>Birth rate or Biotic potential or Fertility or Natality:Biotic potential is the maximum natality or birth rate that can be achieved under ideal conditions of the environment.</li>
	<li>Mortality or Death Rate:In most countries, the death rate dropped almost continuously during the industrial revolution, mainly thue to improved health services.</li>
	<li>Migration: Migration is the movement of individuals into (immigration) or out of femigration) a place or country Immigration minus the emigration is called Net immigration.</li>
	<li>Age and Sex Structures: The age structure of a given population refers to the proportion of individuals of different ages. This is important aspect because many functional aspects like production of lividuals related to age</li>
	<li>Interspecific interactions: In a community different species interact with each other in different ways. </li>
</ol>

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:12px">
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</table>

Ecosystem:

A system produced by the interaction of abiotic and biotic components of an area is called ecosystem. • Ecosystem may be large or small.

<ul>
	<li>Single drop of water may be an ecosystem.</li>
	<li>It is a self-regulatory, self-sustaining and open unit.</li>
</ul>

Homeostasis:

Ecosystem is a dynamic (functional) system because continuous interaction is going on between abiotic or biotic components so the ecosystem remains in an equilibrium position. This feature of the system is known as homeostasis.

<h2>Function of ecosystem</h2>

<ol>
	<li>Productivity: The rate of synthesis of energy containing organic matter or biomass by any trophic level per unit area in unit time describes its productivity. NPP = GPP - R [where, NPP - net primary productivity GPP - gross primary productivity R- Respiratory rate]</li>
	<li>Decomposition: Decomposers break down complex organic matter into inorganic substances like carbon dioxide, water and nutrients and the process is called decomposition. Dead plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter constitute detritus, which is the raw material for decomposition. The important steps in the process of decomposition are fragmentation, leaching, catabolism, humification and mineralisation.</li>
	<li>Mineral Cycling (Biogeochemical Cycles): All the types of materials required by the ecosystem in addition to energy, are available continuously to the system through recycling. Thus there is a constant exchange of materials between the living organism and their abiotic environment through the recycling of materials. These pathways are known as Biogeochemical cycles Note: Environmental factors, eg.. soil, moisture, pH. temperature etc., regulate the rate of release of nutrients into the atmosphere. </li>
</ol>

Hope you learned well. In our next blog we will discuss more about ecology.

Learn the&nbsp;key concepts&nbsp;of ecology

General Science - Learn the key concepts of Ecology

Present blog will make you all aware about the recent technological discoveries in Health Sector, Artificial Intelligence, Automobile Sector, Banking Sector, Energy and Power Sector, Agriculture. 

From blockchain technology to gene-editing to augmented reality, technological advancements have made our lives easier and better in many ways. The term technology comes from the Greek word techne, meaning art and craft, and the word logos, meaning word and speech.

<h2 id="content-id-0">Health Sector</h2>

1. Data-Driven Research to End Tuberculosis- “Dare2eraD TB”: Dr. Jitendra Singh, Union Minister of Science & Technology announced the launch of Data-Driven Research to Eradicate TB- “Dare2eraD TB” by the Department of Biotechnology, M/o Science & Technology.

2. Corbevax was given emergency approval by the DGCI for children aged 12 to 18: The Drugs Controller General of India (DCGI) has authorised Corona Vaccine Biologicals E Ltd Corbeaux for children aged 12 to 18. Corbevax, a coronavirus vaccine developed by the Hyderabad-based pharmaceutical company Biological E Ltd, is also India’s third homegrown vaccine. Covaxin, manufactured by Bharat Biotech, will be administered to children aged 15 to 18 beginning January 3.

3. The Very First Malaria Vaccine W.H.O. approved: The World Health Organization (WHO) recommends that children in Sub- Saharan Africa and other areas with moderate to high P. falciparum malaria transmission receive the RTS,S/AS01 (RTS,S) malaria vaccine. GlaxoSmithKline, a British pharmaceutical company, created the vaccine (GSK). The vaccine protects against Plasmodium falciparum, the most lethal of the five parasite species.

4. The world’s first ‘Plant-based’ smart air purifier created by IIT Ropar: The Indian Institutes of Technology (IIT) Ropar and Kanpur, as well as the Faculty of Management Studies at Delhi University, have collaborated to launch “ubreathe Life,” a living-plant-based air purifier. This air purifier will help to purify the air in indoor spaces such as hospitals, schools, offices, and homes. It is the world’s first cutting-edge ‘Smart Bio-Filter,’ capable of making breathing fresh.

<h2 id="content-id-1">Artificial Intelligence</h2>

1. Artificial Intelligence & Robotics Technology Park: The Indian Institute of Science (IISc) in Bengaluru launched the country’s first Artificial Intelligence and Robotics Technology Park (ARTPARK) with a seed fund of Rs 230 crore. ARTPARK intends to use futuristic technologies to connect the unconnected, with a focus on building India’s world-class Artificial Intelligence and Robotics Innovation ecosystem. The ARTPARK aims to channel innovations to have a societal impact by executing ambitious mission-mode R&D projects in healthcare, education, mobility, infrastructure, agriculture, retail, and cyber-security to solve problems that are unique to India.

2. “PARAM Ganga” Supercomputer installed by C-DAC at IIT Roorkee: At IIT Roorkee, Centre for Development of Advanced Computing (C-DAC) designed and installed the “PARAM Ganga” Supercomputer under Phase II of the National Supercomputing Mission(NSM). PARAM Ganga has 1.66 Petaflops of supercomputing capacity.

3. India’s first AI-based job platform for persons with disabilities - “Swarajability”: The Indian Institute of Technology (IIT-Hyderabad) has released the beta version of ‘Swarajability,’ an artificial intelligence-powered job portal that assists people with disabilities in acquiring relevant skills and finding jobs.

<h2 id="content-id-2">Automobile sector</h2>

Green Hydrogen Fuel Cell Electric Vehicle (FCEV): Nitin Gadkari, Union Minister for Road Transport and Highways unveiled the Toyota Mirai, the world’s most advanced technology-developed Green Hydrogen Fuel Cell Electric Vehicle (FCEV). It is a significant initiative that will promote clean energy and environmental protection by reducing reliance on fossil fuels, making India ‘Energy Self-reliant’ by 2047. Powered by hydrogen, Fuel Cell Electric Vehicle (FCEV) is one of the best Zero Emission solutions. It is entirely environmentally friendly with no tailpipe emissions other than water.

<h2 id="content-id-3">Energy and power sector</h2>

1. India’s first Virtual Smart Grid Knowledge Centre launched in Manesar: As part of the Azadi ka Amrit Mahotsav Programme, Union Minister of Power R.K. Singh launched the Virtual Smart Grid Knowledge Centre (SGKC) and Innovation Park. Power Grid established the SGKC for demonstration and advancement of frontier smart grid technologies.

2. First Start-up of India in Daylight Harvesting Technology: The Ministry of Science and Technology has decided to support a one-of-a-kind start-up in the latest Daylight Harvesting Technology in order to reduce carbon footprint and improve energy efficiency in buildings. The company’s goal is to build green and net-zero buildings, as well as to participate in and contribute to national missions under the National Climate Change Action Plan (NAPCC).

3. ‘AQVERIUM’ - India’s first Digital Water Bank launched in Bengaluru. AquaKraft Ventures, a company that specialises in sustainable initiatives to provide safe drinking water and sanitation to all, spearheaded the initiative. Its goal is to improve the water management system.

<h2 id="content-id-4">Banking sector</h2>

Shaktikanta Das, Governor of the Reserve Bank of India (RBI), launched the Unified Payments Interface (UPI) service for feature phones. The service, known as UPI123Pay, will allow 40 crore feature phone users in India to access the payment service. In addition, the central bank launched DigiSaathi, a 24-hour helpline for digital payments.

About Unified Payments Interface (UPI): UPI is an instant real-time payment system developed by National Payments Corporation of India (NPCI) that allows for inter-bank, peer- to-peer and person-to-merchant transactions. The National Payments Coordinating Council (NPCI) is the umbrella organisation for all digital payments.

<h2 id="content-id-5">Agriculture</h2>

1. Biodegradable nanoparticle developed by IIT Kanpur: Researchers at the Indian Institute of Technology (IIT) Kanpur have developed a biodegradable nanoparticle that can be used instead of chemical-based insecticides to protect crops from bacterial and fungal diseases. Nanoparticles would reduce the risk of crop infection while also increasing agricultural productivity. According to a report released in June 2021 by the United Nations Food and Agriculture Organization (FAO), farmers worldwide lose up to 40% of their crops to insects and illnesses each year. This resulted in a $290 billion loss to the global economy.

2. IIT Roorkee launched ‘KISAN’ mobile app in Uttarakhand: The KISAN app provides farmers with easy access to weather forecasts and weather-based Agrometeorological Advisory Bulletins for all six blocks of the Haridwar district. With the help of Dr. C.S. Jha, an Outstanding Scientist and Chief General Manager at RRSC, NRSC, ISRO, Hyderabad, Dr Khushboo Mirza, Senior Scientist, Regional Remote Sensing Centre (RRSC), National Remote Sensing Centre (NRSC), Indian Space Research Organization (ISRO), New Delhi, developed the app.

Hope you found this blog interesting and informative. Stay connected for more such blogs.

Learn the&nbsp;key concepts&nbsp;of Recent Technological Discoveries

Learn the key concepts of Science topic - Recent Technological Discoveries

Hi dear learners, in our today's blog we will be learning about Stress, Strain, Hooke’s Law, Pressure, Viscosity. So, let's start now.

<h2 id="content-id-0">Stress</h2>

The internal restoring force acting per unit area of a deformed body is called stress.

<ul>
	<li>Stress = Restoring force / Area</li>
	<li>Its unit is N/m2 or Pascal and the dimensional formula is [ML-1T -2].</li>
	<li>Stress is a tensor quantity. (Tensor is a mathematical quantity which is neither scalar nor vector.)</li>
</ul>

Stress is of Two Types:

<ol>
	<li>Normal Stress: If deforming force is applied normal to the area, then the stress is called normal stress. If there is an increase in length due to stress, then stress is called tensile stress. If there is a decrease in length due to stress, then stress is called compression stress.</li>
	<li>Tangential Stress: If deforming force is applied tangentially, then the stress is called tangential stress.</li>
</ol>

<h2 id="content-id-1">Strain</h2>

The fractional change in configuration is called strain.

<ul>
	<li>Strain = Change in the configuration / Original configuration</li>
	<li>It has no unit and it is a dimensionless quantity.</li>
</ul>

According to the change in configuration, the strain is of three types:

<ol>
	<li>Longitudinal strain = Change in length / Original length</li>
	<li>Volumetric strain = Change in volume / Original volume</li>
	<li>Shearing strain = Angular displacement of the plane perpendicular to the fixed surface</li>
</ol>

<h2 id="content-id-2">Hooke's Law</h2>

Within the limit of elasticity, the stress is proportional to the strain. Stress ∝ Strain or, Stress = E × Strain where, E is the modulus of elasticity of the material of the body.

<h2 id="content-id-3">Pressure</h2>

The thrust experienced per unit area of the surface of a liquid at rest is called pressure.

<ul>
	<li>P = F/A</li>
	<li>Its SI unit is N/m2</li>
	<li>When a liquid is in equilibrium, the force acting on its surface is perpendicular everywhere. The pressure is the same at the same horizontal level.</li>
	<li>The pressure at any point in the liquid depends on the depth (h) below the surface, density of the liquid and acceleration due to gravity.</li>
</ul>

<h2 id="content-id-4">Pascal’s Law</h2>

According to Pascal’s Law, the pressure applied to an enclosed liquid is transmitted undiminished to every portion of the liquid and the walls of the containing vessel.

<ul>
	<li>Hydraulic system works on Pascal’s law. Force exerted to area ratio will be the same at all cross sections. Note: A large force is experienced in a larger cross-section if a smaller force is applied in a smaller relation section.</li>
	<li>A column of height h of a liquid of density p exerts a pressure P given.</li>
	<li>Absolute pressure (P) = Gauge pressure (Pg) + Atmospheric pressure (Pa)⇒P g = P - Pa</li>
</ul>

<h2 id="content-id-5">Archimedes principle</h2>

When a body is partially or completely immersed in a liquid, it loses some of its weight. The loss in weight of the body in the liquid is equal to the weight of the liquid displaced by the immersed part of the body. The upward force exerted by the liquid displaced when a body is immersed is called buoyancy. Due to this, there is apparent loss in the weight experienced by the body.

Law of Floatation:

“A body floats in a liquid if the weight of the liquid displaced by the immersed portion of the body is equal to the weight of the body."

<h2 id="content-id-6">Equation of continuity</h2>

According to the equation of continuity, if there is no fluid source or sink along the length of a pipe, then mass of the fluid crossing any section of the pipe per unit time remains constant. i.e. a1 v1p1 = a2 v2p2 

For incompressible liquids (i.e. fluids) p1 = p2 and hence the equation is given as: a1 v1 =a2 v2

It means that the speed of flow of liquid is more where the pipe is narrower, and speed of flow is less where the cross-section of the pipe is more.

<h2 id="content-id-7">Bernoulli’s equation</h2>

For an incompressible, non-viscous, irrotational liquid having streamlined flow, the sum of the pressure energy, kinetic energy and potential energy per unit mass is constant.

<img alt="Bernoulli Theorem Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Bernoulli Theorem Diagram Representation.webp" style="height:40px; width:253px">

For steady flow of a non-viscous fluid along a horizontal pipe, Bernoulli’s equation is simplified as ........

P1 + $1\over2
$pv12 = P2 + $1\over2
$pv22

<h2 id="content-id-8">Viscosity</h2>

Viscosity is the property of the fluid (liquid or gas) by virtue of which an internal frictional force comes into play when the fluid is in motion in the form of layers having relative motion. It opposes the relative motion of the different layers. Viscosity is also called fluid friction. The viscous force directly depends on the area of the layer and the velocity gradient.

<h2 id="content-id-9">Coefficient of viscosity</h2>

Coefficient of viscosity of a liquid is equal to the tangential force required to maintain a unit velocity gradient between two parallel layers of liquid each of area unity.

η= F/A (dv/dx)

<ul>
	<li>The SI unit of coefficient of viscosity is poiseuille (Pl) or Pa-s or Nm-2 s or kg m-1 s-1 .</li>
	<li>Dimensional formula of q is [ML-1T -1].</li>
</ul>

<h2 id="content-id-10">Stokes’ law</h2>

According to Stokes’ law the backward dragging force acting on a small spherical body of radius r moving with a velocity v through a viscous medius of coefficient of viscosity u is given by, F = 6πaηv.

<h2 id="content-id-11">Terminal velocity</h2>

It is the maximum constant velocity acquired by the body while falling freely in a viscous medium. This is attained when the apparent weight is compensated by the viscous force. It is given by: 

Vt = $\sqrt{2mg\over\rho AC_d}$

where p be the density of the material of the body of radius r and o be the density of the medium.

<h2 id="content-id-12">Critical velocity</h2>

The critical velocity is that velocity of liquid flow, upto which its flow is streamline and above which its flow becomes turbulent. It is given by: Vc = kη/ dr where k is a dimensionless constant, η is coefficient of viscosity of liquid, d is density of liquid and r is the radius of tube.

<h2 id="content-id-13">Surface tension</h2>

It is the property of the liquid by virtue of which the free surface of liquid at rest tends to have minimum area and as such it behaves as a stretched elastic membrane. The force acting per unit length of line drawn on the liquid surface and normal to it parallel to the surface is called the force of surface tension.

S = Force/Length = F/L = (Work done)/(Change in area) 

<ul>
	<li>The SI unit of surface tension is Nm-1.</li>
	<li>Its dimensional formula is [MT-2].</li>
</ul>

Torricelli’s Theorem: According to this theorem, velocity of efflux i.e. the velocity with which the liquid flows out of on orifice (a narrow hole) is equal to that which a freely falling body would acquire in falling through a vertical distance equal to the depth of orifice below the free surface of liquid. The velocity is given by: V = √2gh

Magnus Effect: When a ball is given a spin when it is in a streamline of air molecules, it will follow a curved path which is convex towards the greater pressure side. This idea is the basis of the ball from spin bowlers in cricket getting a lift and aerodynamics.

After reading about the general properties of matter, we discussed mechanical properties of solids starting with defining some basic concepts and definitions about them. Then we discussed the concepts of stress, strain and the types of moduli of elasticity. Stay tuned for more.

Learn the&nbsp;key concepts&nbsp;of Pressure

Learn the key concepts of Science topic -  Pressure

Environmental chemistry is a science that deals with various chemical phenomena occurring in the environment. It includes the study of sources and effects of certain specific chemical species, called pollutants, on air, water and soil. By definition, the pollutant is a substance produced either by a natural source or by human activity which has an adverse effect on the environment and causes environmental pollution.

<h2 id="content-id-0">Classification of Environment</h2>

1. Atmosphere: The atmosphere is a gaseous mixture of air that surrounds the earth. The different layers of atmosphere are as follows:

<ul>
	<li>Troposphere: It is the lowest region of the atmosphere extending from the earth’s surface to the lower boundary of the stratosphere. It contains water vapors and is greatly affected by air pollution. It extends up to the height of ~ 10 km from sea level.</li>
	<li>Stratosphere: The layer of the earth’s atmosphere above the troposphere and below the mesosphere, is called the stratosphere. The ozone layer is present in this region.</li>
	<li>Mesosphere: It is the region of the earth’s atmosphere above the stratosphere and below the thermosphere. It is the coldest region (temperature – 2 to – 92°C) of the atmosphere.</li>
	<li>Thermosphere: The upper region of the atmosphere above the mesosphere is called the thermosphere. It is the hottest region (temperature up to 1200°C).</li>
	<li>Exosphere: It is the uppermost region of the atmosphere. It containts atomic and ionic O2 ,H2 and He.</li>
</ul>

2. Hydrosphere: It is the aqueous envelope of the earth, e.g. oceans, lakes, etc.

3. Lithosphere: The solid rocky portion of the earth constitutes the lithosphere.

4. Biosphere: The biological envelope which supports life is called the biosphere. e.g. animals, human beings.

Environmental Pollution: It may be described as contamination of the environment with harmful wastes mainly arising from certain human activities. These activities release materials that pollute the atmosphere, water and soil.

<h2 id="content-id-1">Types of pollutions</h2>

(i) Natural pollution: This type of pollution is caused by natural sources, e.g. volcanic eruptions, the release of methane by paddy fields and cattle, forest fires, etc.

(ii) Man-made pollution: This type of pollution is resulting from human activities like the burning of fuels, deforestation, industrial effluents, pesticides etc.

<h2 id="content-id-2">Pollutants</h2>

Any substance produced either by a natural source or by human activity which causes adverse effects on the environment is called a pollutant. Pollutants can be of the following types depending upon the following factors Classification based on Their Degradation:

(i) Biodegradable pollutants: Pollutants capable of being degraded by biological or microbial actions are called biodegradable pollutants. e.g. domestic sewage.

(ii) Non-biodegradable pollutants: The substances which are normally not acted upon by microbes are called non-biodegradable pollutants. These undergo biological magnification.

<h2 id="content-id-3">Air pollution</h2>

Air pollution occurs when the concentration of a normal component of the air or a new chemical substance added or formed in the air, builds up to undesirable proportions causing harm to humans, animals, vegetation, and materials.

Air Pollutants: The chemical substances and particles causing pollution are called air pollutants. The major air pollutants are:

(i) Oxides of Sulphur: The most common species is Sulphur dioxide (SO2 ). It is produced by petrol combustion, coal combustion, petrol refining, and smelting operation. 2SO2 + O2 2SO3

(ii) Oxides of nitrogen: NO2 and NO are obtained by combustion of coal, gasoline, natural gas, petroleum refining, chemical industries and tobacco smoke. In the upper atmosphere, these are emitted by high flying jets and rockets. Breathing NO2 causes chlorosis to plants and chronic lung conditions leading to death in human beings. These oxides destroy the ozone (O3 ) layer. 2NO(g) + O2 2NO2 (g) NO(g) + O3 (g) NO2 (g) + O2 (g)

(iii) Smoke and dust: Fume, Dust and smoke is a solid form of Aerosol and Mist is a liquid form of aerosol. These are obtained in cement works, iron and steel works, gas works, power generating stations. Coal miners suffer from black lung disease and textile workers suffer from white lung disease.

(iv) Ammonia: It is produced by fertilizer works.

(v) Mercaptans: These are obtained from oil refineries, coke ovens etc.

(vi) Zn and Cd: These are obtained from zinc and cadmium industries.

(vii) Freon (or CFC’s): Their source is a refrigerator.

(viii) Hydrocarbons: These are formed by the incomplete combustion of fuel used in automobiles. These are carcinogenic. They harm plants and also break down tissues.

(ix) Oxides of Carbon: (a) Carbon monoxide (CO) (b) Carbon dioxide (CO2 )

<h2 id="content-id-4">Greenhouse effect and Global Warming</h2>

The phenomenon in which the atmosphere of earth traps the heat coming from the sun and prevents it from escaping into outer space is called the greenhouse effect. Certain gases, called greenhouse gases [carbon dioxide, methane, ozone, chlorofluorocarbon compounds (CFCs) and water vapour] in the atmosphere absorb the heat given by earth and radiate back to the surface of the earth. Thus, warming of the earth led to the warming of air due to greenhouse gases, which is called Global Warming.

Greenhouse gases: CO2 , CH4 (most abundant hydrocarbon pollutant in the atmosphere), N2O, HCFCs, HFCs, Water vapour (most abundant greenhouse gas in atmosphere)

Acid Rain:

The pH of normal rain water is 5.6 due to the formation of H ions by dissolution of CO2 from the atmosphere. when the pH of rain water drops below 5.6 it is called acid rain (by Robert Augus.) Oxides of Nand S are responsible for making rainwater acidic. Much of the NOx and SOx entering the atmosphere are converted into HNO3 and H2SO4 respectively. The detailed photochemical reactions occurring in the atmosphere are given as: NO+O3 ⇒ NO2+O2 2NO2+O2 ⇒2NO3NO2+NO3 ⇒ N2O5 N2O5 + H2O ⇒ 2HNO3

<h2 id="content-id-5">Particulate pollutants</h2>

These are the minute solid particles or liquid droplets in air. Particulates in the atmosphere may be viable or non-viable.

<ol>
	<li>Viable particulates: bacteria, fungi, algae etc.</li>
	<li>Non-viable particulates: smoke, dust, mists, fume. </li>
</ol>

Smog: It is a mixture of smoke (composed of tiny particles of carbon, ash and oil etc from coal combustion) and fog in suspended droplet form. It is of two types:

Stratospheric Pollution: (Depletion of Ozone Layer) Ozone is a light bluish gas and absorbs UV radiations of the sun which are harmful to living beings, but nowadays the ozone layer is being depleted by CFCs (chlorofluorocarbons).

UV radiations cause the chlorofluorocarbons to dissociate to form highly reactive chlorine free radicals which react with ozone to form chlorine monoxide.

<h2 id="content-id-6">Ozone hole</h2>

The major stratospheric ozone layer over Antarctica was discovered in 1985. Ozone holes are formed over Antarctica, and some parts of non-polar regions also. In other parts of stratosphere, NO2 , CH4 react with ClO* and Cl* respectively and act as natural sink for ClO* . Ozone holes are formed due to increased exposure of direct UV rays on earth. The main cause of ozone depletion is manufacturing of CFCs like chemicals.

Consequences of Depletion of Ozone Layer: 

<ol>
	<li>Loss of sight: The UV radiation damages the cornea and lens of the eyes.</li>
	<li>Effect on immune system: The UV radiations are also likely to suppress the immune system.</li>
	<li>Skin cancer: UV radiation is known to be a cancer-causing agent.</li>
</ol>

<h2 id="content-id-7">Water pollution</h2>

The contamination of water by foreign substances which would constitute a health hazard and make it unfit for all purposes (domestic, industrial or agriculture etc) is known as water pollution. The polluted water may have foul odour, bad taste, unpleasant colour etc. 

Control of Water Pollution:

<ol>
	<li>Recycling of wastewater.</li>
	<li>Use of chemicals: Lead poisoning can be cured by giving the patient an aqueous solution of calcium complex of EDTA. Lead ions displace calcium in the EDTA complex to form chelated lead and Ca+2. The soluble lead chelate is excreted with the urine.</li>
	<li>Special techniques such as adsorption, ion exchangers, reverse osmosis, electrodialysis etc.</li>
	<li>Wastewater reclamation.</li>
</ol>

Soil or Land Pollution: The addition of substances in an indefinite proportion changes the productivity of the soil. This is known as soil or land pollution.

Cleansing Agents: The word detergent means cleansing agent. Actually, detergent is derived from the Latin word ‘detergent’ which means “to wipe off”.

<h2 id="content-id-8">Soaps</h2>

Soaps are sodium or potassium salts of higher fatty acids (containing large number of carbon atoms) e.g. stearic acid, oleic acid and palmitic acid. Sodium salts of fatty acids are known as hard soaps while potassium salts of fatty acids are known as soft soaps. Soft soap is a soap that is liquid or readily soluble, usually produced by saponification with potassium rather than sodium hydroxide on the other hand, hard soap, also known as curd soap, is a form of soap.

Preparation of soaps:Soaps containing sodium salts are formed by heating fat (glyceryl ester of fatty acid) with an aqueous sodium hydroxide solution. This reaction is known as saponification.

<h2 id="content-id-9">Types of soaps</h2>

Different types of soaps are made by using different raw materials.

<ol>
	<li>Toilet soaps: These are prepared by using better grades of fat or oil and care is taken to remove excess alkali. Colour and perfumes are added to make these more attractive.</li>
	<li>Floating soaps: These can be prepared by beating tiny air bubbles into the product before it hardens. </li>
	<li>Transparent soaps: These are made by dissolving the soap in ethanol and then evaporating the excess solvent.</li>
	<li>Medicated soaps: Medicated soaps are prepared by adding some antiseptics like dettol or bithional.</li>
	<li>Shaving soaps: These contain glycerol to prevent rapid drying. A gum called rosin is added while making them. It forms sodium rosinate which lather well.</li>
	<li>Laundry soaps: These contain fillers like sodium rosinate, sodium silicate, borax and sodium carbonate.</li>
	<li>Soap chips: These are made by running a thin sheet of melted soap on a cool cylinder and scraping off the soaps in small broken pieces.</li>
	<li>Soap granules: These are dried miniature soap bubbles.</li>
	<li>Soap powder and scouring soaps: These contain a scouring agent (abrasive) such as powdered pumice or finely divided sand and builders like sodium carbonate and trisodium phosphate. Builders increase the cleansing action of soaps by making them act more quickly.</li>
</ol>

We also described the causes of soil/ land pollution. We also appreciated the importance of chemistry in day-to-day life.

Learn the&nbsp;key concepts&nbsp;of&nbsp;Environmental chemistry

Learn the key concepts of Science topic -  Environmental chemistry

Today in biology section, we will be dealing with nutrient immobilization, ecological succession, biodiversity. So, dive deep and learn some most interesting facts about these topics.

<h2 id="content-id-0">Nutrient immobilization</h2>

In the process of decomposition, some nutrients get tied up with the biomass of microbes and become temporarily unavailable to other organisms. Such incorporation of nutrients in living microbes (bacteria & fungi) is called nutrient immobilization.

(A) Carbon Cycle:

Carbon is present in the lithosphere in the form of coal and petroleum. The carbon released from them is found in the atmosphere in the form of carbon dioxide. Autotrophs utilize CO2 , from the air to synthesize food materials which are obtained by other organisms as food. Carnivores obtain their organic food from the herbivores. These organic matter produce CO2 , through the oxidation or respiration which dissolves in the air or water and again utilized by the plant

(B) Phosphorus Cycle: 

Phosphorus is the main constituent of protoplasm, plasma membrane, bones and teeth. Main source of phosphorus is rocks. It comes from the weathering of phosphorus containing rocks in the soil. Plants absorb this phosphorus from the soil and transfer this phosphate to animals and after the death of animals it is released again into the lithosphere by the action of decomposers. Sometimes some of the elements like phosphorus and calcium reach into the sea through water from where they transform into rocks. They separate from the cycle for a long time so it is also known as the sedimentary cycle. But when these rocks break after sometime then this phosphorus is again made available to the sea plant or sea weeds, which pass into fish and sea birds. The excretory materials of birds on the rocks of the sea shore is called Guano and it is a source of phosphorus.

Note: Plants absorb phosphate from the soil in the form of orthophosphate.

(C) Nitrogen Cycle:

<img alt="Nitrogen Cycle Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Nitrogen Cycle Diagram Representation.webp" style="height:125px; width:200px">

<h2 id="content-id-1">Ecological succession</h2>

The gradual and fairly predictable change in the species composition of a given area is called ecological succession.

<ul>
	<li>Pioneer community: The community that invades a bare area is called pioneer community.</li>
	<li>Seral communities: The entire sequence of communities that successively change in a given area are called sere(s). In the successive seral stages there is a change in the diversity of species of organisms, increase in the number of species and organisms as well as an increase in the total biomass.</li>
</ul>

<h2 id="content-id-2">Types of succession</h2>

On the basis of the area on which succession occurs, it is of two types- Primary and Secondary:

(i) Primary Succession: It starts where no living organisms are there-these could be anvas where no living organisms ever existed e g.newly cooled lava, bare rock, newly created pond or reservoir. The establishment of a new biotic community is generally slow. Before a biotic community of diverse organisms can become established, there must be soil. Depending mostly on the climate, it takes natural processes several hundred to several thousand years to produce fertile soil on bare rock.

(ii) Secondary Succession: Secondary succession begins in areas where natural biotic communities have been destroyed such as in abandoned farm lands, bumed or cut forests, lands that have been flooded. Since some soil or sediment is present, succession is faster than primary succession. The species that invade depend on the condition of the soil, availability of water, the environment as also the seeds or other propagules present. Since soil is already there, the rate of succession is much faster and hence, climax is also reached more quickly.

Based on the nature of the habitat-whether it is water (or very wet areas) or it is on very dry areas-succession of plants is called hydrarch or xerarch, respectively. As against this, xerarch succession takes place in dry areas and the series progress from seric to mesic conditions. Hence, both hydrarch and xerarch succession lead to medium water conditions (mesic)-neither too dry (xeric) nor too wet (hydric).

<h2 id="content-id-3">Biodiversity</h2>

The combined diversity at all levels of biological organization ranging from biomacromolecules to biomes is known as biodiversity or heterogeneity.

Loss of Biodiversity:

<ul>
	<li>The biodiversity has been declining rapidly due to human activities.</li>
	<li>The IUCN Red List (2004) documents the extinction of 784 species (including 338 vertebrates, 359 Invertebrates and 87 plants) in the last 500 years. </li>
	<li>The last twenty years alone have witnessed the disappearance of 27 species.</li>
	<li>Some examples of recent extinctions include the Dodo (Mauritius), Quagga (Africa). Thylacine (Australia), Steller’s Sea Cow (Russia) and three subspecies (Ball, Javan, Caspian) of Tiger.</li>
</ul>

Causes of biodiversity loss:

<ol>
	<li>Habitat loss and fragmentation</li>
	<li>Over-exploitation </li>
	<li>\Alien Species Invasions</li>
	<li>Co-extinctions</li>
</ol>

Biodiversity Conservation:

<img alt="Biodiversity Conservation Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Biodiversity Conservation Diagram Representation.webp" style="height:176px; width:250px">

(A) Ex-Situ Conservation: In this approach, threatened animals and plants are taken out from their natural habitat and placed in a special setting where they can be protected and given special care. Zoological parks, botanical gardens and wildlife safari perks serve this purpose. There are many animals that have become extinct in the wild but continue to be maintained in zoological parks. Other examples of exsitu conservation are gene banks, germplasm banks, seed banks. Gametes of threatened species can be preserved in viable and fertile condition for long periods using cryopreservation techniques, eggs can be fertilized in vitro, and plants can be propagated using tissue culture methods. Seeds of different genetic strains of commercially important plants can be kept for long periods in seed banks.

B) In-situ conservation: It is the protection of species in their natural habitat by making their habitats protected areas for example- National park, Sanctuaries, Biosphere Reserves etc.

National Park: They are areas maintained by the government and reserved for the betterment of wildlife. Cultivation, grazing, forestry and habitat manipulation are not allowed.

Sanctuaries: They are tracts of land with or without lakes where wild animals/fauna can take refuge without being hunted. Other activities like collection of forest products, harvesting of timber, private ownership of land, tilling of land, etc. are allowed.

Biosphere Reserves: They are multipurpose protected areas which are meant for preserving genetic diversity in representative ecosystems of various natural biomes and unique biological communities. by protecting wild populations, traditional lifestyle of tribals and domesticated plant/animal genetic resources. It is a specified protected area in which multiple use of the land is permitted.

There are 3 zones in a Biosphere Reserve

<img alt="Biosphere Reserve Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Biosphere Reserve Diagram Representation.webp" style="height:105px; width:200px">

<ol>
	<li>Core Zone: It lies at the center where no human activity is allowed.</li>
	<li>The Buffer zone: Where limited human activity is allowed.</li>
	<li>Manipulating zone or Transition zone: Where a large number of human activities would go on.</li>
</ol>

Hence by studying ecology we got to know about general ecosystems, our biodiversity, different flora and fauna, their habitat and interaction among themselves and environment etc. In the next blog we will learn about Human Physiology and its important components. We will learn the mechanism of different systems of human body and their pivotal role in human body. So, stay tuned with us.

Learn the&nbsp;key concepts&nbsp;of&nbsp;ecological succession

Learn the key concepts of Science topic -  Ecological succession

Today we will be study about the space technology. Let's start and explore.

Space technology refers to technology that can be used for travel or activities beyond Earth’s atmosphere, such as space flight or space exploration. Exploring other planets, studying the universe, and providing communication and navigation services to support human activities are all possible with space technology. It includes everything from satellites and other instruments to astronautics, physics, chemistry, and biology, as well as the human aspects of space travel. Space technology encompasses the research and development of new technologies, as well as new applications for existing technologies and technological advancements for current space systems. Deep space communication, in-space propulsion, and a wide range of other technologies, such as support infrastructure equipment and procedures, are all examples of space technology.

<h2 id="content-id-0">History of space tech in India</h2>

India has become a significant global player in space science and technological (S&T) developments. India formally coordinated its various organisations related to space programmes in 1972 by constituting the space commission and the Development of Space (DOS). Both of these institutes direct and regulate India’s space programme.

Vikram Sarabhai—founder of the Physical Research Laboratory at Ahmedabad—and Homi Bhabha, who established the Tata Institute of Fundamental Research in 1945 organised space research in India.

ISRO’s timeline of Space Programme from 1960s to 2022:

1960’s: Journey of the formation of ISRO

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:18px">
	<tbody>
		<tr>
			<td>
			Year
			</td>
			<td>
			About Mission
			</td>
		</tr>
		<tr>
			<td>
			1962
			</td>
			<td>
			Vikram Sarabhai, commonly regarded as the "Father of India's Space Program," and scientist Kalpathi Ramakrishna Ramanathan founded the Indian National Committee for Space Research.
			</td>
		</tr>
		<tr>
			<td>
			1963
			</td>
			<td>
			Thumba Equatorial Rocket Launching Station in Kerala launched the first sounding rocket for probing upper atmospheric areas for space exploration. It was the first step in India's space programme.
			</td>
		</tr>
		<tr>
			<td>
			1965
			</td>
			<td>
			On January 1, 1965, the Space Science and Technology Centre (SSTC) was founded at Thumba.
			</td>
		</tr>
		<tr>
			<td>
			1967
			</td>
			<td>
			Isro and Tata institute of Fundamental Research operated balloon launch at Hyderabad base.
			</td>
		</tr>
		<tr>
			<td>
			1968
			</td>
			<td>
			Ahmedabad, Gujarat, an experimental satellite communication earth station was set up.
			</td>
		</tr>
		<tr>
			<td>
			1969
			</td>
			<td>
			The Indian Space Research Organisation (ISRO) was established with the goal of utilising space technology for national development.
			</td>
		</tr>
	</tbody>
</table>

1970s: Era of launching Satellites began

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none">
	<tbody>
		<tr>
			<td>
			Year
			</td>
			<td>
			About Mission
			</td>
		</tr>
		<tr>
			<td>
			1971
			</td>
			<td>
			In Sriharikota, Andhra Pradesh, the Satish Dhawan Space Centre was established.
			</td>
		</tr>
		<tr>
			<td>
			1972
			</td>
			<td>
			The Department of Space (DoS) was established and ISRO brought under it.
			</td>
		</tr>
		<tr>
			<td>
			1975
			</td>
			<td>
			The first Indian satellite, Aryabhata, was launched into space on April 19th.It was a defining moment in India's space programme because it was designed entirely in India and launched from a Russian facility.
			</td>
		</tr>
		<tr>
			<td>
			1979
			</td>
			<td>
			Bhaskara-I, the first experimental remote-sensing satellite developed in India, was launched. The photos it sent are used in hydrological, forestry, and oceanographic research.
			</td>
		</tr>
	</tbody>
</table>

1980s: Launch of Satellite launch Vehicle, Communication satellite, remote sensing satellite.

<table cellspacing="0" class="Table" style="border-collapse:collapse; border:none; margin-left:16px">
	<tbody>
		<tr>
			<td>
			Year
			</td>
			<td>
			About Mission
			</td>
		</tr>
		<tr>
			<td>
			1980
			</td>
			<td>
			India's first experimental satellite vehicle, the Satellite Launch Vehicle-3 (SLV-3) was launched, making ISRO the country's sixth space agency. SLV-3 launched a second time with Rohini. The mission was successful.
			</td>
		</tr>
		<tr>
			<td>
			1981
			</td>
			<td>
			Rohini was placed into orbit.
			</td>
		</tr>
		<tr>
			<td>
			1982
			</td>
			<td>
			Communication Satellite Insat-1A was launched.
			</td>
		</tr>
		<tr>
			<td>
			1983
			</td>
			<td>
			Rohini was launched into orbit on SLV-3's second developmental mission.
			</td>
		</tr>
		<tr>
			<td>
			1984
			</td>
			<td>
			India and the Soviet Union have undertaken a joint manned mission. Rakesh Sharma, India's first cosmonaut, spent eight days in the Russian space station Salyut 7.
			</td>
		</tr>
		<tr>
			<td>
			1987
			</td>
			<td>
			ASLV was launched with the SROSS-1 satellite.
			</td>
		</tr>
		<tr>
			<td>
			1988
			</td>
			<td>
			Indian Remote Sensing Satellite IRS-1A was launched
			</td>
		</tr>
	</tbody>
</table>

<h2 id="content-id-1">Indian Space Research Organisation</h2>

The Indian Space Research Organisation (ISRO), located in Bengaluru, is the country’s first space exploration organisation. ISRO was established in 1969 with the goal of developing and utilising space technology for national development while also pursuing planetary exploration and space science research. ISRO was founded after INCOSPAR (Indian National Committee for Space Research), which was founded in 1962 by India’s first Prime Minister, Pt. Jawaharlal Nehru, and scientist Vikram Sarabhai, considered amongst the founding fathers of the Indian space program. 

7 Mega Missions of ISRO:

ISRO’s Chandrayaan-2, XPoSat (to research cosmic radiation in 2020), and Aditya-L1 are among its seven mega missions (to the Sun in 2021).

Undefined Missions — These include missions such as Mangalyaan-2 (or Mars Orbiter Mission-2 in 2022), Lunar Polar Exploration (or Chandrayaan-3 in 2024), Venus mission (in 2023), and Exoworlds, which are currently in the planning stages (exploration outside the solar system in 2028).

Xposat: ISRO’s dedicated mission to examine polarisation is the X-ray Polarimeter Satellite (or Xposat). The X-ray Polarimeter Satellite (XPoSat) is a space observatory being developed by ISRO to research the polarisation of cosmic X- rays. It will be launched on a Small Satellite Launch Vehicle (SSLV) in the second quarter of 2022 and will have a service life of at least five years.

Aditya- L1 Mission: It’s the country’s first solar mission. Its goals are to research the sun’s outermost layers, the corona and chromospheres, as well as collect data on coronal mass ejection, which will help anticipate space weather. The data from the Aditya mission will be extremely useful in distinguishing between various hypotheses for the origin of solar storms, as well as constraining how the storms evolve and what course they take across interplanetary space from the Sun to the Earth.

<h2 id="content-id-2">Basics of orbits</h2>

An orbit is a regular, repeating path that one object in space takes around another one. An object in an orbit is called a satellite. A satellite can be natural, like Earth or the moon. Many planets have moons that orbit them. A satellite can also be man-made, like the International Space Station.

What Shape is an Orbit?

Orbits come in a variety of forms. All orbits are elliptical, which means they are shaped like an ellipse. The orbits of the planets are approximately round. Comets’ orbits are shaped differently. They are “squashed,” or very odd. They resemble thin ellipses rather than circles. Satellites orbiting Earth, including the moon, do not always stay the same distance from Earth.

How do Objects Stay in Orbit?

Newton’s first law of motion states that unless something pushes or pulls on it, an object in motion will stay in motion. Without gravity, an Earth-orbiting satellite would go in a straight line into space. It gets dragged back to Earth by gravity. A constant tug-of-war takes place between the satellite’s tendency to move in a straight line, or momentum, and the tug of gravity pulling the satellite back.

<h2 id="content-id-3">Types of orbits</h2>

When a satellite or spacecraft is launched, it is usually positioned in one of several orbits around Earth — or it may be sent on an interplanetary mission, in which it orbits the Sun instead of Earth until it reaches its eventual destination, such as Mars or Jupiter.

Geostationary Orbit (GEO): Geostationary satellites (GEO) circle the Earth above the equator from west to east in 23 hours, 56 minutes, and 4 seconds, travelling at the same rate as the Earth. To perfectly match the rotation of the Earth, GEO satellites should travel at a speed of about 3 km per second at an altitude of 35,786 km. This is much farther away from the Earth’s surface than many satellites.

Lower Earth Orbit (LEO): A lower Earth orbit (LEO) is an orbit that is close to the Earth’s surface, as the name implies. It is normally less than 1000 km above Earth, but it can be as low as 160 km above Earth – which is low in comparison to other orbits, but still very far above the Earth’s surface.

In comparison, most commercial planes do not fly at altitudes much higher than 14 km, so even the lowest LEO is more than ten times higher. Unlike GEO satellites, which must always orbit along Earth’s equator, LEO satellites do not always have to follow the same path around Earth – their plane can be tilted. This means that satellites in LEO have more available routes, which is one of the reasons why LEO is such a commonly used orbit.

Medium Earth Orbit (MEO): Medium Earth orbit encompasses a wide range of orbits ranging from LEO to GEO. It is similar to LEO in that it does not require specific paths around Earth, and it is used by a wide range of satellites with a variety of applications.

Polar orbit and Sun-synchronous Orbit (SSO): Polar orbiting satellites typically travel from north to south rather than west to east, passing roughly over the Earth’s poles.

Satellites in polar orbit do not have to pass exactly through the North and South Poles; a deviation of 20 to 30 degrees is still considered a polar orbit. Polar orbits are a type of low Earth orbit because they are at low altitudes ranging from 200 to 1000 kilometres. This is because, if you want to monitor an area by taking a series of images of a specific location over many days, weeks, months, or even years. comparing somewhere at midnight and then at midday is not very useful – you need to take each picture as similarly as the previous picture as possible.

Satellites in SSO are frequently synchronised so that they are constantly in dawn or dusk – this is because they will never have the Sun at an angle where the Earth shadows them if they are constantly riding a sunset or sunrise. A satellite in a Sun-synchronous orbit would typically be located at an altitude of 600 to 800 km. It will travel at a speed of approximately 7.5 km per second at 800 km.

Transfer orbits and Geostationary Transfer Orbit (GTO): Transfer orbits are orbits that are utilised to transition from one orbit to another. Satellites are not always placed directly on their ultimate orbit when launched from Earth and taken to space by launch vehicles like Ariane 5. Satellites are frequently placed in a transfer orbit, which allows the satellite or spacecraft to transition from one orbit to another with relatively little energy from onboard engines. With such a very eccentric orbit, the satellite can suddenly shift from being extremely far away to being very close to the Earth’s surface, depending on where it is in the orbit. In transfer orbits, the payload utilises engines to move from one eccentric orbit to another, putting it on course for higher or lower orbits. On the blue elliptical orbit, the apogee is the point farthest away from Earth, while the perigee is the point closest.

<h2 id="content-id-4">Satellite</h2>

A satellite is a body that orbits around another body in space. Natural and man-made satellites are the two sorts of satellites. The Earth and the Moon are examples of natural satellites. The Earth revolves around the Sun, whereas the Moon revolves around it. A man-made satellite is a spacecraft that is launched into orbit around a celestial body. The Hubble Space Telescope and the International Space Station are examples of man-made satellites.

<h2 id="content-id-5">Types of Satellite</h2>

1. Astronomical: Used to study distant planets, stars, galaxies, and other objects in-universe. It’s a space telescope that hangs in space and takes pictures of objects in space.

2. Biosatellite: A satellite that sends animals or plants into space to study the effects of space on these living things.

3. Communication: These satellites support telecommunication. Telecasting, phone calls, Internet access, radio, and a wide range of remote connectivity are all common uses.

4. Earth Observation: Deployed to study the environment, monitor climatic changes and mapping the earth for non military purposes.

5. Navigation: Facilitates the exact location of any objects on the Earth. As a result, new applications, technologies, and business cases are developed.

6. Killer (Military): During the conflict, it was used to strike hostile satellites and space objects.

7. Space Stations: Designed for human beings to live and conduct research on objects on planets, stars, and galaxies.

8. Reconnaissance: Deployed for spying, surveying and scouting enemy territory during the war period.

9. Crewed Spacecraft: These satellites ferry astronauts to space and bring them back to earth. It has excellent grounding capabilities and assists astronauts in gaining access to space stations.

10. Recovery: Recovery satellites are primarily used to recover bio, reconnaissance and other satellites back to earth.

11. Solar Power: Space-based satellites gather energy from the Sun and transmit it to earth for consumption.

12. Miniaturised: Smaller and lighter satellites are launched at a low cost for the limited purpose of scientific data collection and radio relay.

Satellite Launching Vehicles: 

In 1980, the first experimental Satellite Launch Vehicle (SLV- 3) was built. In 1992, an augmented version of this, ASLV, was successfully introduced. With the operationalization of the Polar Satellite Launch Vehicle (PSLV) and Geosynchronous Satellite Launch Vehicle (GSLV), India has achieved enormous progress in launch vehicle technology to achieve self-reliance in satellite launch vehicle programmes.

<h2 id="content-id-6">Initial launch vehicles of India</h2>

Satellite Launch Vehicle (SLV): SLV-3 (Satellite Launch Vehicle- 3) was India’s first experimental satellite launch vehicle, a four-stage, all-solid-fuel vehicle capable of launching payloads up to 40 kg into Low Earth Orbit (LEO). When the Rohini satellite, RS-1, was sent into orbit in 1980, India became the sixth member of an exclusive club of space-faring nations.

Augmented Satellite Launch Vehicle (ASLV): The ASLV is a five-stage, all-solid-fuel rocket capable of launching 150 kg satellites into circular orbits 400 kilometres in diameter. The ASLV Program was created to increase the payload capacity for Low Earth Orbits to 150 kg, three times that of SLV-3 (LEO).

Operational Launch Vehicles of India: ISRO currently uses two launch vehicles: the PSLV (Polar Satellite Launch Vehicle) and the GSLV (Geosynchronous Satellite Launch Vehicle), both of which can be configured in a variety of ways. PSLV has been ISRO’s most reliable rocket to date, with 52 of its 54 launches proving successful. The GSLV is a significantly more powerful rocket designed to transport heavier satellites further into space. GSLV rockets have launched 18 missions to date, four of which have failed.

We studied about differenent technologies such as Biotechnology, Defence, Nuclear, Energy and recent discoveries, now we will try to solve some previous year questions. Stay tuned for more.

Learn the&nbsp;key concepts&nbsp;of&nbsp;Space technology&nbsp;

Learn the key concepts of Science topic - Space technology

When we throw a ball up in the air it always comes back to the ground. This happens due to a force known as gravity. This same force makes it possible for us to walk on earth. Gravitation due to moon causes tides in oceans. In this blog, we would understand and learn about the force of gravitation in detail.

<h2 id="content-id-1665-0">Gravitation</h2>

Throw a ball vertically upwards in the air. It rises up and again falls downwards. The question arises here that why does the ball fall down. Why does it not go upwards?

This question got an answer in the year 1665 when Sir Issac Newton provided the theory of gravitation to the world. According to his theory, earth attracts everything towards itself with a force known as ‘gravity’. Due to this force of gravity the ball doesn’t go upwards after covering some vertical distance. Actually every massive object attracts every other massive object towards itself with this force.

Newton’s Law of Gravitation:

The gravitational force of attraction between any two bodies in the Universe is directly proportional to the product of their masses and inversely proportional to the square of distance between them. If two bodies having masses m1 and m2 whose centers are at a distance r from each other, the gravitational force will be: 

F ∝ M1 x M1

F ∝ 1/r2 (Inverse square law)

F ∝ M1M1/r2

F = G × [M1M2]/r2

The force is along the line joining the two particles. (Here G is the gravitational constant)

Universal Law of Gravity:

Every object in the universe attracts every other object with a force which is proportional to the product of their masses and inversely proportional to the square of the distance between them. The force is along the line joining the centres of two objects.

<ul>
	<li>G is the constant of proportionality, known as the universal gravitational constant.</li>
	<li>G = 6.673 × 10-11 Nm2/kg2 (In S.I system) = 6.67 × 10-8 dyne cm2/g2 (In C.G.S. system)</li>
	<li>Dimension of G = [M-1L 3T -2]</li>
	<li>The law of gravitation is applicable for all bodies, irrespective of their shape, size and position.</li>
</ul>

<h2 id="content-id-1665-1">Kepler's law of Planetary motion</h2>

First Law (Law of Orbits): The orbit of a planet is an ellipse with the sun at one of the foci.

Second Law (Law of Area): The line joining the planet and the sun sweeps equal areas in equal intervals of time.

Third Law (Law of Periods): The square of its time periods of revolution around the sun is directly proportional to the cube of the mean distance of a planet from the sun.

If r is the average distance of the planet from the sun and T is the time period of revolution then, T2 ∝ r 3 .

Earth’s Gravitational Acceleration (Acceleration due to Gravity): 

According to Newton’s second law of motion, a force acting on a body results in its acceleration. Thus, the gravitational force due to earth on a body results in its acceleration. This is called acceleration due to gravity and is denoted by ‘g’. Acceleration is a vector. g is directed towards the centre of the earth.

<img alt="Gravitation Law Diagram Representation" src="https://study.kdcampus.live/admin/assets/uploads/ckeditor/Gravitation Law Diagram Representation.webp" style="height:114px; width:200px">

<h2 id="content-id-1665-2">Mass and weight</h2>

The quantity of matter in a body is known as the mass. Mass is a quantitative measure of inertia. Higher the mass, higher will be the inertia. Mass is an intrinsic property of matter and doesn’t change as an object is moved from one location to another.

The weight of an object is defined as the force with which the earth attracts the object.

The force (F) on an object of mass m on the surface of the earth can be written as Weight (W) = F = mg, (g = GM/R2 ) Weight being a force, its SI unit is Newton and is a vector quantity. Its direction is towards the centre of the earth. As the value of g is not the same everywhere, the weight of an object changes from place to place, though its mass remains constant everywhere. Since the value of g on the moon is 1/6th of the value of g on earth, the weight of an object on the moon is 1/6th of the weight on the earth.

<h2 id="content-id-1665-3">Escape velocity</h2>

When we keep on increasing the velocity of an object thrown upwards, a stage will arrive when the object will reach height so large that it will escape the gravitational field of the Earth and will not fall back on the Earth. This initial velocity is called the escape velocity.

<ul>
	<li>Escape velocity of earth = √(2 × 9.8 × 6.4 × 106 ) = 11.2 km/s.</li>
	<li>For the Moon, the Escape Velocity is 2.4 km/s</li>
	<li>Escape Velocity of satellite Ve = √(2gr) [R = radius of earth]. Ve = √2V0 i.e. √2 times of the orbital velocity.</li>
</ul>

Therefore, if the orbital velocity of a satellite is increased to √2 times (increased by 41%), the satellite will leave the orbit and escape.

Weightlessness in Space:

Space travellers as well as objects in the spacecraft appear to be floating. Why does this happen? Though the spacecraft is at a height from the surface of the earth, the value of g there is not zero. In the space station the value of g is only 11% less than its value on the surface of the earth.

Hope all your doubts related to this topic are clear. Stay for more such informative blogs.

Learn the&nbsp;key concepts&nbsp;of Gravitation

Learn the key concepts of Science topic -  Gravitation

Hi guys, hope you all are studying well. Many of you have doubts related to Main group elements. So today's blog will clear all your doubts related to this topic. Let's explore deep then.

Main group elements have been grouped into 8 vertical columns, called groups. These groups are IA (1), IIA (2), IDA (13), IV(14), VA(15), VIA(16), VILA (17), and zero (18). These elements are placed at the extreme left and extreme right of the periodic table.

<h2 id="content-id-0">s-block elements</h2>

In the s-block elements, the last electron enters the s-orbital. As the s-orbital can accommodate only two electrons, two groups (1 and 2) belong to the s-block. The general electronic configuration of s-block elements is ns1 or 2 .

Group-1 (Alkali Metals):

Group-I elements have one electron in their valence shell. They do not occur in the native or free state. These elements are collectively known as alkali metals because their oxides and hydroxides form strong alkalies like NaOH, KOH, etc. Lithium is known as a Bridge element.

Important compounds of alkali metals:

1. Sodium Chloride or Table Salt (NaCl): Sea water contains 2.7 to 2.9% by mass of the salt. Sodium chloride is obtained by evaporation of sea water but due to the presence of impurities like CaCl2 and MgCl2 , it has a delicate nature. It is purified by passing HCl gas through the impure saturated solution of NaCl and due to common ion effect, pure NaCl gets precipitated. The 28% NaCl solution is called brine.

Uses: 

<ul>
	<li>As an enhance of flavour and as a preservative for food.</li>
	<li>To clear the ice on high-ways, which blocks the roads during winter.</li>
	<li>As physiological solution (0.9% NaCl in water), as it is iso-osmotic with blood-plasma.</li>
</ul>

2. Sodium Hydroxide or Caustic Soda [NaOH]: 

Method of Preparation: Electrolytic process involves Nelson cell and Castner-Kellner cell. A brine solution is electrolyzed using a mercury cathode and a carbon anode. Sodium metal discharged at the cathode combines with Hg to form Anamalgam. Chlorine gas is evolved at the anode. The amalgam is treated with water to give sodium hydroxide and hydrogen gas. 2Na-Hg + 2H2O→ 2NaOH + 2Hg + H2

Uses:

<ul>
	<li>It is used as a reagent in the laboratory.</li>
	<li>It is used in the manufacture of soap, paper, dyes, fat, and oils, etc.</li>
</ul>

3. Sodium Bicarbonate or Baking Soda (NaHCO3 ): 

Method of Preparation: It is obtained as an intermediate product in the Solvay process.

Uses: 

<ul>
	<li>It is used as a constituent of baking powder which is a mixture of sodium bicarbonate, starch and potassium bitartrate or cream of tartar and in medicine to remove acidity of the stomach (as antacid).</li>
	<li>NaHCO3 is a mild antiseptic for skin infections </li>
	<li>It is used as a fire extinguisher.</li>
</ul>

Group-II (Alkali earth metals):

Group-II elements are Be, Mg, Ca, Sr, Ba and Ra, which have two electrons in their valence shell. These are commonly called alkaline earth metals because their oxides are alkaline in nature and are found in earth’s crust.

Uses of Alkaline Earth Metals:

<ul>
	<li>Beryllium (Be) is used in corrosion resistant alloys.</li>
	<li>Alloy of Mg with aluminium is used as structural material because of its high strength, low density and ease in machining.</li>
	<li>Strontium carbonate is used for the manufacture of glass for colour TV picture tubes.</li>
	<li>Magnesium is present in chlorophyll, a green pigment in plants, essential for photosynthesis.</li>
	<li>Anhydrous CaCl2 because of its hygroscopic nature is a good drying agent but it cannot be used to dry alcohols/ ammonia/ amines.</li>
</ul>

Important compounds of alkali earth metals:

Calcium Oxide or Quicklime or Lime (CaO): It is a basic oxide. Its aqueous suspension is known as slaked lime. On heating with ammonium salts, it gives ammonia. It reacts with carbon to form calcium carbide.

CaO + 3C CaC2 + CO 

Calcium Hydroxide or Slaked Lime or Limewater (Ca(OH)2 ): Its suspension in water is known as milk of lime. It gives CaCO3 (milky) and then Ca(HCO3 ) 2 with CO2 . It reacts with Cl2 to give bleaching powder,

CaOCl2 . Ca(OH)2 + Cl2 CaOCl2 + H2O

Calcium Carbonate or Limestone or Marble or Chalk [CaCO3 ]: It is insoluble in H2O but dissolves in the presence of CO2 , due to the formation of calcium bicarbonate.

Gypsum, Calcium Sulphate Dihydrate (CaSO4 .2H2O): It is also known as alabaster. On heating at 390 K, it gives the plaster of Paris. It is added to cement to slow down its rate of setting

Plaster of Paris or Calcium Sulphate Hemihydrate (CaSO4 .½ H2O): When it is mixed with water, it first forms a plastic mass which sets into a solid mass with slight expansion due to dehydration and its reconversion into gypsum. It is obtained when gypsum is heated at 393 K.

CaSO4 .2H2O CaSO4 . ½ H2O + 3/2H2O

Above 393 K, no water of crystallization is left and anhydrous calcium sulphate is obtained. It is known as dead burnt plaster.

Bleaching Powder (CaOCl2 ): Its aqueous solution gives Ca2+, Cl- and OCl- ions. With limited quantity of dil. H2 SO4 , it gives nascent oxygen which is responsible for its oxidising and bleaching action. With excess of dil H2 SO4 (or CO2 ), it forms Cl2 , which is known as available chlorine. Ca(OH)2 + Cl2 CaOCl2 +H2O

Cement: Cement is an important building material. It is a product obtained by combining materials such as limestone (lime and clay provides alumina and silica, SiO2 along with the oxides of iron and magnesium.

<h2 id="content-id-1">p-block elements</h2>

In p-block elements, the last electron enters in the outermost p-orbital. There are six groups of p-block elements in the Periodic Table, numbering from 13 to 18. Their valence shell electronic configuration is ns1-2np1-6 (except for He). In this part of main group elements, we will only study variations and characteristics properties of Group-15 and Group-17 elements.

Group-15: The 15 group of the periodic table consists of nitrogen, phosphorus, arsenic, antimony and bismuth. These elements are known as pnictogens and their compounds as pnictides.

Group-17: The 17 group of Periodic Table contains five elements fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and astatine (As) collectively known as halogens (salt forming elements). Astatine is an artificially prepared radioactive element

In this blog, we understood and learned about recent trends and properties of the main group element in detail. Stay connected for more.

Learn the&nbsp;key concepts&nbsp;of Main group elements