Pseudopodia, or fake feet, is Amoeba's locomotory organ. As a result, protoplasm streaming in amoeba is a rudimentary sort of mobility. The surface of the fake feet, or pseudopodia, forms due to the...
Write locomotory organ of Amoeba.
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Previous Year Question Papers
Describe the role of decomposers in ecosystem.
A decomposer's involvement in the environment is as follows: -To begin with, they clean the environment by decomposing dead plants and animals. -They aid in the nutrient recycling process. -By...
Write two excretory substances of human being.
Kidneys are among the organs of the human excretory system. Kidneys are bean-shaped structures that are protected by the ribs and back muscles on either side of the spine. Every single person.The...
Write the name of respiration which occurs in presence of . oxygen.
Aerobic Respiration
Write name of disease which occurs due to deficiency of vitamin A.
Ans. Eczema and other skin problems are caused due to vitamin A deficiency that leads to dry, itchy skin.
Distinguish between Metal \& Non – metal on the basis of Chemical Properties.
Ans. Non-metals aren't very durable. Their tensile strength is modest. Metals are ductile and malleable. 1. Non-metals aren't malleable or ductile in the same way as metals are. Metals are excellent...
Write down the anomalies of mendeleev’s Periodic Table.
Ans. The Mendeleev periodic table has the following flaws: Pairs that aren't supposed to be together Mendeleev's Principles are not followed by the following pairs of elements: Nickel (58.6) is...
What is Hydrogenation? What is its industrial application?
Ans. The chemical reaction between hydrogen and other molecules in the presence of a catalyst is known as hydrogenation. The process of hydrogenation is primarily used to decrease saturated...
What do you understand by catalyst?
Ans. Catalysts are chemicals that change the rate of a reaction by altering the reaction path. A catalytic reaction occurs when a catalyst is present in a system, and the phenomenon is known as...
What is replacement reaction?
Ans. A replacement reaction is a chemical reaction in which one element in a compound replaces another. A single replacement reaction or a double replacement reaction can be used to accomplish this.
Write down the atomic number of calcium.
Ans. 20
Write down the name of a non – metal which is found in liquid state at normal temperature.
Ans. Non-metal which exist as a liquid at room temperature is bromine.
Balance the following equation- CO2+H20 ?C6H12O6+H2O+O2
Ans. 6CO2+12H2O=C6H12O6 +6O2+6H20
Write down the molecular formula of Plaster of Paris.
Ans. Plaster of Paris is calcium sulphate hemihydrate. Its chemical formula is: CaSO4.21H2O.
What is Galvanisation?
Ans. Galvanization is the process of coating a metal with a protective layer of zinc. It is a standard way of protecting iron from rusting. This can be accomplished by either dipping the metal to be...
Write down the anomalies of Mendeleev’s Periodic Table.
Ans. The Mendeleev periodic table has the following flaws: Pairs that aren't supposed to be together Mendeleev's Principles are not followed by the following pairs of elements: Nickel (58.6) is...
Explain Conductor, Non – conductor, Semi – conductor and Super – conductor with example.
Ans. Materials that allow electricity to flow freely through them are referred to as electrical conductors. Conductivity is the property of conductors that allows them to conduct electricity. The...
What is Electric Generator? Explain principle of its function. Describe its structure and working procedure.
Ans. An electric generator is a device that generates electric energy that can be stored in batteries or directly delivered to homes, stores, workplaces, and other locations. Electromagnetic...
Write difference between Alterating and Direct current.
Ans. The fundamental distinction between the two is the direction in which the current flows. Direct current, also known as DC, flows in one direction uniformly, whereas alternating current, also...
What do you mean by Electric charge? Write types of Electric charge.
Ans. When matter is placed in an electromagnetic field, it acquires an electric charge, which causes it to experience a force. Positive and negative charges are the two forms of electric charge...
Write formula of relation hetween focal length and radius of curvature in concave mirror.
Ans. In both cases focal length is equal to the half of the radius of curvature. i.e, R = 2f.
What is magnification? Explain it.
Ans. Magnification is the process of enlarging something's apparent size rather than its true size. This enlargement is measured by a numerical value known as "magnification." When this value is...
Which lens is known as diverging lens?
Ans. concave lens
Write full form of AIDS.
Ans. Acquired Immunodeficiency Syndrome
What is commercial unit of electrkal energy?
Ans. The commercial unit of electrical energy is kilo watt hour (kWh).
How many Laus of refraction of light are there?
At the interface of two transparent media at the point of incidence, the refracted ray, incident ray, and normal all lie in the same plane.
What are the materials used for the preparation of bleaching powder?
Materials used for the preparation of bleaching powder are calcium hydroxide and chlorine.
(a) What is the chemical name of bleaching powder? (b) What is the chemical formula of bleaching powder?
(a) The chemical name of bleaching powder is Calcium oxychloride. (b) The chemical formula of bleaching powder is $\mathrm{CaOCl}_{2}$.
Draw a diagram of a vertical section of the human brain and label the following parts. a) Cerebrum b) Cerebellum
The image represents the vertical section of the human brain. The parts cerebrum and the cerebellum is shown in the image.
Draw a labelled diagram of neuromuscular junction.
Transport of food from leaves to other parts of the plant is called _________.
Correct answer is Translocation
What do you mean by biological magnification?
When the main exposure route is through the organism's meal, biomagnification occurs when the chemical concentration in the organism surpasses the chemical concentration in its food.
How is food transported in plants?
Phloem is involved in the distribution of food to different parts of the plant. The transportation of food in phloem is an active process achieved by utilizing energy from ATP which helps in...
Approximately how much large is whole digestive system in a healthy human?
The digestive system is made up of alimentary canal and other organs such as liver and pancreas. The alimentary canal is the long tube of organs including esophagus, stomach and intestines that run...
How is brain protected in our body?
The skull well protects the human brain. Inside the skull, the brain is covered by cranial meninges consisting of an outer layer called dura mater, a very thin middle layer called arachnoid and the...
The human brain weight approximately ……….% of the body weight.
The adult human brain weighs about 3 pounds (1,300-1,400 g). The adult human brain is about 2 % of the total body weight. The average human brain is 140 mm wide. So, the correct answer is 2%.
Describe the structure of human brain
The brain is made of three main parts: the forebrain, midbrain, and hindbrain. The forebrain consists of the cerebrum, thalamus, and hypothalamus. The midbrain consists of the tectum and tegmentum....
Draw a labelled diagram of human digestive system and explain it.
(i). Food is crushed and cut in the mouth with the help of teeth and is mixed with saliva that is secreted by three salivary glands(one below the tongue and two at the side of the jaw) to make it...
Distinguish between self-pollination and cross-pollination.
Pollen from the anther is deposited on the stigma of the same bloom or another flower on the same plant, resulting in self-pollination. The transfer of pollen from the anther of one flower to the...
Given reasons for adopting contraceptive methods ?
Contraceptive methods include any approach to prevent conception; for example, oral contraceptive pills, surgical methods (vasectomy, tubal ligation), contraceptive implants, diaphragm, cervical...
Name two plant hormones along with their functions.
There are several Plant Hormones classes, namely, Auxin, Cytokinin, Gibberellin, Abscisic Acid, Ethylene. Here are the functions of plant hormones in short. Functions of Auxin: Cell enlargement,...
Do you find that all living beings need the same kind of food?
No, all living beings do not need the same kind of food. They have different food requirements. Depending on their food requirements, they are classified as: 1) Herbivores: Animals that eat only...
Differentiate between autotrophic nutrition and heterotrophic nutrition ?
Autotrophs can prepare their own food because of the presence of chlorophyll within their cells. Heterotrophs can not prepare their own food due to the absence of chlorophyll, hence indirectly...
Write the steps involved in the extraction of metals from their ores.
The following are the steps involved in extracting metals from their ores: (1) Powdering of ores – Ores are crushed into small bits. With the use of a ball mill or a stamp mill, these bits are...
What are the following reactions? ![\[(5 \times 1=5)\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-8b94dc54eb89fe5418388c6d6da5fecd_l3.png "Rendered by QuickLaTeX.com")
(i) Addition reaction (ii) Substitution reaction (iii) Esterification reaction
Sol. I Addition reactions are those in which a reactant molecule is added to another reactant molecule to generate a product. Addition reactions occur in unsaturated hydrocarbons like alkenes and...
How the electronic configuration of an atom is related to its position in the Modern Periodic table.
Sol. Electronic configuration No. of mass - period no. No. of valence - group No
Draw the structure of Benzene and Cyclohexane.
Give two ways to prevent iron from rusting.
Sol. Two ways to prevent iron from rusting (i) By painting or greasing (ii) By alloying
Why distilled water does not conduct electricity, whereas rain water does?
Sol. Distilled water does not contain any dissolved salts so it does not conduct electricity. Rain water contains dissolved impurities which are capable of conducting electricity.
Differentiate between washing soda and baking soda.
\begin{tabular}{|l|l|l|} \hline & \multicolumn{1}{|l|}{ Baking Soda } & \multicolumn{1}{c|}{ Washing soda } \\ \hline Chemical formula & \multicolumn{1}{|c|}{$\mathrm{NaHCO}_{3}$} &...
Write one equation each for decomposition reaction and combination reaction.
Sol. Decomposition reaction: $\mathrm{CaCO}_{3}(\mathrm{~s}) \stackrel{\Delta}{\longrightarrow} \mathrm{CaO}(\mathrm{s})+\mathrm{CO}_{2} \uparrow$ Combination reaction : $3...
(a) Draw a well labelled diagram of human eye.(b) Flow do ciliary muscles accommodate focal length of eye lens to see nearby objects and far objects?
Ans. (a) Human eye diagram (b) By changing the curvature of lens.
Why does the sun appear reddish early in the morning?
Ans. As the distance of travel through the atmosphere increases during dawn and dusk. Light is scattered much more than during noon. As the shorter wavelengths are scattered, only red light is left,...
What is an earth wire? What is its function?
Ans. Earth wire is a low resistance wire which connects an appliance to earth so that all the excess current passes to the earth from the wire instead of human body and hence saves from shock.
An electric lamp with voltage rating 
is connected to main supply of 
. What current is drawn by the lamp from the main supply?
$$ beginarrayl P=fracV2R 60=frac220times 220R R=frac220times 22060 V=I R quadRightarrow quad I=frac110times 60220times 220=frac322 A 110=I=frac220times 22060 quadRightarrow quad endarrayl $$
What is electric current? Write SI unit of electric current.
Ans. Electric current is the rate of change flowing through a conductor at a specific place. $$ \s\mathrm{I}=\frac{\mathrm{q}}{\mathrm{t}} $$ Ampere is the SI unit for it.
Draw a ray diagram for image of an object placed on-the principal axis of a convex mirror. Write the nature, position and size of the image formed by the mirror.
Ans. Nature - Virtual and Errect Position - B/W focus and pole. Size - Diminished
Define refractive index. The refractive index of diamond is 
. What is the meaning of this statement?
Ans. A material's refractive index is a dimensionless number that describes how quickly light propagates through it. It is the ratio of the speed of light in vacuum to the speed of light in a...
Why is a normal eye not able to see clearly the objects placed closer than 
?
Due to the power of accommodation in the eye, a normal eye cannot see well objects that are closer than $25 mathrmcm$.
. Why do we prefer a convex mirror as a rear-view mirror in vehicles?
Ans. We utilise convex mirrors as rear-view mirrors because they provide a decreased picture and can cover a vast region.
Why is a normal eye not able to see clearly the objects placed closer than ?
Ans. Due to the eye's ability to accommodate, a normal eye cannot see clearly objects that are closer than $25 mathrmcm$.
Why do we prefer a convex mirror as a rear-view mirror in vehicles?
We utilise convex mirrors as rear-view mirrors because they provide a decreased picture and can cover a vast region.
For total internal reflection to take place, the angle of incidence 
and the refractive index 
of the medium must satisfy the inequality
A 
B 
c 
D 
Correct option is A $\frac{1}{\sin i}\frac{1}{\mu}$ $$ \Rightarrow \frac{1}{\sin i}
Total internal reflection can take place only if ?
Total internal reflection can take place only if (1) Light goes from optically denser medium to rarer medium (2) Angle of incidence is greater than the critical angle
Assertion (A): Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface. Reason (R) : Refractive index of the material of the core of the optical fibre is greater than that of air.
Both (A) and (R) are true but (R) is not the correct explanation of Propagation of light through an optical fibre is due to total internal reflection taking place at the interface of cable and air....
In optical fibres, propagation of light is due to which phenomenon ?
Optical fibre is a device which transmits light introduced at one end to the opposite end, with little loss of the light through the sides of the fibre. It is possible with the help of total...
Name the principle on the basis of which optical fibres work.
Optical fibres works on the principle of total internal reflection. When light ray strikes at the internal surface of optical fibre cable called such that incidence angle is greater than critical...
Name the physical principle on which the working of optical fibres is based.
The physical principle on which the working of optical fibres is based is, repeated total internal reflection of light.
Optical fiber communication is based on which of the phenomena:-
Total internal reflection
The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light:
The amount of scattering is inversely proportional to the fourth power of wavelength. And since the wavelength of red has the longest wavelength, the amount of scattering becomes smaller. Danger...
Why Red Signals are used as danger sign? Explain.
Red light is used as danger signal because it is having high wavelength, less scattering ,hence can travel larger distances.
Derive an expression for energy stored in a charged condenser. Obtain its different forms.
Let 'C' is the capacitance of the capacitor. Let 'Q' and 'V' be the charge and potential difference respectively. Let 'q' be the charge on the capacitor at some stage during charging and 'v' is the...
Derive an expression for energy stored in a capacitor. In which form energy is stored?
Let us consider a capacitor of capacitance C and potential difference V between the plates. Let the charge on one plate be +q and -q on the other. Suppose the capacitor is being charged gradually....
State the laws of refraction of light.
Incident ray, reflected ray, refracted ray and the normal of the system lie in the same plane.
What is meant by refraction of light? State the laws of refraction.
Refraction: The phenomenon of change in the direction of light when it passes from one transparent medium to another is called refraction. Laws of refraction: (i) The incident ray, the refracted ray...
Describe the reflection of light on the basis of Huygen’s wave theory.
Reflection at plane surface As shown in figure, consider a plane wavefront $A B$ incident on the plane reflecting surface AY, both the wavefront and the reflecting surface being perpendicular to the...
Explain the problem of refraction of light the basis of Huygen’s secondary wavelets theory and verify Snell’s law of refraction .
Refraction at plane Surface We will now use Huygens principle to device the laws of refraction. Let PP' represent the surface separating medium 1 and medium 2 as shown in figure 12.4. Let...
Where is the near point of a person suffering from hypermetropia (or long-sightedness)?
Hypermetropia or Long Sightedness is an eye defect. A person suffering from it can see distant objects clearly but is not able to see nearby objects clearly. The near point of a person suffering...
Complete the following sentence : (I). A short-sighted person cannot see …………… object clearly. Short-sightedness can be correct by using ……….. lenses. (II). A long-sighted person cannot see ………….. object clearly. Long-sightedness can be corrected by using ………… lenses.
(a) A short-sighted person cannot see close objects clearly. Short-sightedness can be corrected by using the concave lens in front of the eyes. (b) A long-sighted person cannot see far objects...
Write true or false for the following statements : For a person suffering from myopia, the image of the object is formed in front of the retina.
True In myopia person is not able to see far away objects due to elongation of the eyeball . The image is formed in front of the retina as shown in the figure below.
What is the far point of a person suffering from myopia (or short-sightedness)?
The far point of a person suffering from myopia or short- sightedness is less than infinity. In myopia the person is able to see close by objects clearly but they are not able to see distant objects
A person having short-sightedness cannot see objects clearly beyond a distance of 1.5 m. What would be the nature and power of the corrective lens used to restore proper vision?
Concave lens should be used to restore proper vision. Calculation of power: Object distance, $u=-\infty$ Image distance, $\mathrm{v}=-1.5 \mathrm{~m}$ $$ \begin{array}{l}...
What is short-sightedness? State the two causes of short-sightedness (or myopia)
Short Sightedness is that defect of vision due to which a person can see nearby objects clearly but cannot see distant objects clearly. Causes: 1. Excessive curvature of the eye lens 2. Elongation...
Does short-sightedness (myopia) or long-sightedness (hypermetropia) imply necessarily that the eye has partially lost its ability of accommodation? If not, what might cause these defects of vision?
The ability of the eye lens to adjust its focal length is called accommodation. No, short-sightedness (myopia) or long-sightedness (hypermetropia) does not imply necessarily that the eye has...
Long-sightedness is to hypermetropia as short-sightedness is to :
Long-sightedness is also called hypermetropia short-sightedness is also called myopia
What is a long-sighted eye ? State one cause of long-sightedness. Name the lens used for correcting long-sightedness.
An eye is said to be long-sighted if the image of a nearby object is formed behind the retina. It is caused because the eye lens cannot widen enough to reduce the focal length i.e. it is too thin or...
Name the type of lens which is used to correct? i) Myopia ii) Hypermetropia.
Concave lens is used to correct myopia and convex lens is used to correct hypermetropia.
A man can see objects clearly up to 3m. What type of lens he should use in order to see clearly up to 12m?
Clearly, the lens used should be the concave lens. Actual far point $$ \mathrm{u}=-12 \mathrm{~m} $$ Far point of the person, $$ \mathrm{v}=-3 \mathrm{~m} $$ We have lens formula, $$...
A person suffering from myopia cannot see beyond 
. What should be the focal length of the concave lens that will correct his vision?
So when the object is placed at infinity a image should be formed at $1 \mathrm{~m}$ away from eyes. So, $u=\infty$ $$ \mathrm{v}=-1 \mathrm{~m}=-100 \mathrm{~cm} $$ we know that...
How does concave lens correct myopia?
A Increases the curvature of the eye lens
B Forms the image of the object at the retina
C Decreases the elongation of the eyeball
D All of the above Correct option is (B) Forms the image of the object at the retina
A person with myopia cannot see distant objects clearly since the far point for that person is nearer than infinity. Such a person may see clearly up to a distance of a few meters. In this...
Give reasons: A concave lens is used to correct myopia.
In a myopic eye, the image of a distant object is formed in front of the retina and not at the retina itself. A concave(diverging) lens causes light rays to diverge before they strike the lens of...
Which of the following lens is used to minimise myopia?
A Convex lens
B Concave lens
c Cylindrical lens
D Planar lens
Correct option is (B) Concave lens Near-sightedness, also known as short-sightedness and myopia, is a condition of the eye where light focuses in front of, instead of on, the retina. This causes...
Which of the following lens is used to correct myopia?
A Convex lens
B Concave lens
C Cylindrical lens
D None of these
Correct option is B Concave lens In Myopia, the image of a nearby object is formed ahead of the retina. By placing a concave (negative powered) lens in front of a myopic eye, the image is moved...
To remove hypermetropia lens used is –
(A) Convex
(B) Concave
(C) Cylindrical
(D) Plano-convex
Correct option is (A)Convex lens In Hypermetropia, the image of a nearby object is formed behind the retina. By placing a convex (plus powered) lens in front of a hypermetropic eye, the image is...
Write short notes on any two or the following: iii) Bio-diversity
Answer: "Biological Diversity" is what makes up biodiversity. It is the diversity of all living things, as well as the system that connects them. As a result, biodiversity encompasses more than just...
Write short notes on any two or the following: ii) National garden
Answer: Botanical gardens are collections of living plants that are kept for research purposes. Botanical gardens have the following functions: They provide on-site teaching opportunities regarding...
Write short notes on any two or the following: i) Greenhouse gases
Answer: The greenhouse gases in the atmosphere trap heat and warm the earth. Carbon dioxide, methane, nitrous oxide, and water vapour (all of which exist naturally) are the principal greenhouse...
Write an essay on evolution of man.
Answer: Man is the result of natural selection. As a result, human evolution is inextricably linked to the origin of life and its spread across the globe. It's common to talk about evolution in...
Comment upon DNA fingerprinting.
Answer: In genetics, DNA fingerprinting is a method of extracting and identifying variable regions within the base-pair sequence of DNA. It is also known as DNA typing, DNA profiling, genetic...
Write an essay on genetic code.
Answer: The nucleotide sequences of the mRNA determine the amino acid sequences of the protein. The genetic code, which was deciphered by Marshall Nirenberg and his colleagues in the early 1960s, is...
Comment upon any two of the following: iii) Antibody.
Answer: An antibody (Ab), also known as an immunoglobulin (Ig), is a big, Y-shaped protein that helps the immune system recognise and eliminate foreign substances like bacteria and viruses. The...
Comment upon any two of the following: ii) Bt crops
Answer: Bt Crops are transgenic plants that generate the same toxin as the Bacillus thuringiensis bacterium in the plant cell, protecting the plants from pests. The bacterium produces poisonous "cry...
Comment upon any two of the following: i) Transgenic animals
Answer: Animals (most typically mice) that have had a foreign gene purposely put into their genome are known as transgenic animals. Microinjection of DNA into the pronuclei of a fertilised egg,...
. Write notes on any two of the following iii) Plasmid.
Answer: A plasmid is a tiny extrachromosomal DNA molecule that can replicate independently of chromosomal DNA and is physically isolated from it. Plasmids are small circular double-stranded DNA...
Write notes on any two of the following : i) Hot spots
Answer: Biogeographic regions of the earth that serve as a substantial store of biodiversity but are also threatened with extinction are known as biodiversity hotspots (or biodiversity hotspots).......
Write the names of three types of RNA found in a cell and mention the function of each.
Answer: RNA types and functions. The three most well-known and studied kinds of RNA are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA), all of which are found in all species....
Discuss the law of dominance and law of segregation propounded by Mendel.
Answer: law of segregation This legislation is founded on four fundamental ideas: • When gametes are created by meiosis, the allelic pairings split, leaving each gamete with a single allele. • For...
Describe in brief the origin of life on Earth.
Answer: Examining life on our own planet has proven to be the most fruitful strategy. However, because life began at least 3.5 billion years ago, it is difficult to trace its origins even in our own...
What is the theory of Natural selection ? Who had propounded this theory ?
Answer: Natural selection is the process through which individuals with various phenotypes survive and reproduce differently. The change in the heritable features characteristic of a population over...
Explain that phosphorus is an essential factor for biotic components of an Ecosystem. Draw a line diagram of plrosphorus cycle.
Answer: Restriction enzyme, also known as restriction endonuclease, is a bacterial protein that cleaves DNA at particular points along the molecule. Restriction enzymes cut foreign DNA in the...
Discuss the role of Biotechnology in the field of agriculture.
Answer: To defend itself against bacterial viruses known as bacteriophages, or phages, a bacterium uses a restriction enzyme. When a phage infects a bacterium, it inserts its DNA into the cell in...
What do you mean by restriction enzyme? Explain its importance.
Answer: A restriction endonuclease is a bacterial protein that cleaves DNA at specified locations along the molecule. Restriction enzymes cut foreign DNA in the bacterial cell, removing invading...
Define pollution. Explain the problem of air pollution occurring in big citics of the country.
Answer: The presence of compounds in the atmosphere that are damaging to human and other living beings' health, or that damage the climate or materials, is referred to as air pollution. Gases (such...
Differentiate between the following: ii) Benign tumour (cancer) and malignant tumour (cancer).
Answer. Tumors can be benign (noncancerous) or cancerous (cancerous) (cancerous). The majority of benign tumours grow slowly and do not spread. Malignant tumours can spread throughout the body,...
Differentiate between the following: i) Innate immunity and acquired immunity
Answer: Innate immunity is an individual's inborn resistance to illnesses that he or she has from birth as a result of his or her genetic or constitutional make-up. Acquired immunity is the ability...
Write short notes on the following: ii) Fisheries.
Answer: Fishery can refer to either the business of growing or harvesting fish and other aquatic life, or the location where such business is conducted (a.k.a. fishing ground). Commercial fisheries...
Write short notes on the following: i) Role of micro-organisms in Bio. gas production
Answer: 1. During their growth, development, and metabolism, microbes produce a variety of gaseous end-products. 2. Anaerobic bacteria that grow on cellulosic materials produce huge volumes of...
Write the names of any two pathogens causing diseases in humans and comment upon their regulation.
Answer: A pathogen causes illness in its host. Pathogens are also known as infectious agents because they cause infections. Pathogens emphasise survival and reproduction, just like any other...
How does the development of endosperm take place in Angiospermic plants? Differentiate between endospermic and nonendospermic seeds with examples.
Answer:Double Fertilization When the two sperm nuclei inside a pollen particle reach the interior of a female gametophyte (also known as the embryo sac), endosperm is created. Polyploid endosperm...
Family planning is in national interest. Justify.
Answer . Through Hum Do (/humdo.nhp.gov.in/), the National Family Planning Programme seeks to provide eligible couples with information and guidance on family planning methods and services to ensure...
Draw only a line diagram of development of a female gametophyte.
What is biofortification ?
Answer: Breeding crops to boost their nutritional worth is known as biofortification. This can be accomplished using either traditional selective breeding or genetic engineering. Biofortification...
Differentiate between parasitism and commensalism.
Answer. Parasitism is a relationship between two species in which one benefits from the other and the other suffers as a result. When two species contact, one benefits while the other is neither...
Describe in brief the morphological adaptations in Hydrophytes.
Answer: The sponginess of all hydrophytes' tissues is an important anatomical trait. Their leaves, stems, and roots have a lot of air gaps in them. This aids in the maintenance of plant buoyancy and...
Define spermatogenesis
Answer: The ultimate stage of spermatogenesis is spermiogenesis. It's when spermatids turn into mature, motile spermatozoa. The nucleus, Golgi apparatus, centriole, and mitochondria are all present...
Which organigm causes the typhoid fever ?
Answer: Typhoid is a bacterial infection caused by the bacteria Salmonella typhi.
Who is called the father of Ecology in India?
Answer: At maturity, the pericarp of fleshy fruits is fleshy. There are four sorts of simple fleshy fruits. Berry, drupe, pome, and hip are the four types. One or more carpels with one or more seeds...
Write only two characteristic features of a fleshy fruit and draw the labelled diagram of a vertical section of a mango fruit.
A) Define external fertilization with an example
Answer: External fertilisation is a type of reproduction in which the sperm of a male creature fertilises the egg of a female organism outside of the female's body. Internal fertilisation, on the...
Antibiotics are mainly obtained form i) Blue-grecn algae ii) Bacteria iii) Bryophyta iv) Viruses
Answer: ii) Bacteria Explanation- Antibiotics are chemicals that are produced by an organism and prevent the growth of other organisms. They're usually obtained from bacteria or other microbes.
Parthenogenesis occurs in i) Honeybee ii) Frog iii) Lizard iv) nonc of these.
Answer: i) Honeybee Explanation- Parthenogenesis is a reproductive method in which a female (rarely a male) gamete (sex cell) develops without being fertilised. It's most prevalent in lower plants...
In which of the following insects pollination takes place? i) Gurhal ii) Fig iii) Wheat iv) Hydrilla.
Answer: ii) Fig Explanation- The nectar provides energy while the pollen provides protein. Wasps are also important insect pollinators, pollinating many species of figs.
The most dangerous reason for the cxistence of lives is i) Desertation ii) Radiation iii) Deforestation iv) none of these.
Answer: iii) Deforestation Explanation- Because they are all connected, deforestation causes desterification, and radiation or nuclear pollution created by radioactive materials has an impact on...
Parthenogenesis occurs in i) Honeybee ii) Frog iii) Lizard iv) nonc of these.
Answer: i) Honeybee Explanation- Parthenogenesis is a reproductive method in which a female (rarely a male) gamete (sex cell) develops without being fertilised. It's most prevalent in lower plants...
In which of the following insects pollination takes place? i) Gurhal ii) Fig iii) Wheat iv) Hydrilla.
Answer: ii) Fig Explanation- The nectar provides energy while the pollen provides protein. Wasps are also important insect pollinators, pollinating many species of figs.
The most dangerous reason for the cxistence of lives is i) Desertation ii) Radiation iii) Deforestation iv) none of these.
Answer: iii) Deforestation Explanation- Because they are all connected, deforestation causes desterification, and radiation or nuclear pollution created by radioactive materials has an impact on...
Establish the laws of reflection of light on the basis of wave theory.
The reflected wave front must be built in the following manner, as shown in Figure: - I Draw an arc of a circle with a radius equal to DE from B as the centre. (ii) Draw the tangent EF to the arc...
What do you mean by 
-type and 
-type semiconductors ? Explain the working of a 
junction diode.
Extrinsic P-Type Semiconductors are made when a small amount of a trivalent impurity is added to a pure semiconductor, resulting in a significant number of holes. The addition of trivalent...
What is the use of a step-up transformer?
In generating stations and other power transmission applications, step up transformers are commonly utilised. The lower voltage is provided to the primary windings of power transformers at power...
What do you mean by intensity of electric field ?
The electric field is the area around an electric charge where its impact can be felt. The field of electricity The force experienced by a unit positive charge put at a certain point is called...
Explain end-on position and broad side-on position of a bar magnet.
Consider a bar magnet of length 2l and pole strength m. Suppose a point P on the axis of the magnet at a distance d from its center. (d –l) is the distance of P form the N-pole of the magnet.
What do you mean by magnetic elements of the earth ?
The magnetic declination, magnetic dip, and magnetic intensity or one of its components at any location on the earth's surface are all magnetic elements.
Write short notes on the following : v) Coenzymes of electron transport system.
Answer: Within the mitochondrial membrane, oxidative phosphorylation is a process involving the flow of electrons through the electron transport chain, a sequence of proteins, and electron carriers....
Write short notes on the following : iv) Photolysis of water
Answer: Water photolysis is the splitting of water molecules into hydrogen ions, oxygen, and electrons in the presence of light or photons. Any photon with enough energy can break any compound's...
What is the principle of conservation of charge?
The overall quantity of electric charge in a system does not change over time, according to the conservation of charge principle. Charged particles can be generated at the subatomic level, but only...
Write short notes on the following : iii) Absorption of light through chlorophyll molecules
Answer: In stage 1, light is absorbed by chlorophyll a molecules bound to reaction-center proteins in the thylakoid membrane. The energized chlorophylls donate an electron to a quinone on the...
Write short notes on the following : ii) Munch hypothesis
Answer: The best-supported explanation for explaining sap passage through the phloem is the pressure flow hypothesis, often known as the mass flow hypothesis. Ernst Münch, a German plant...
What is light year ?
A light-year is the distance light travels in one Earth year.
Write short notes on the following : i) Leghaemoglobin
Answer. Leghaemoglobin is a pigment present in the root nodules of leguminous plants that is red in colour. It mixes with oxygen and aids in the elimination of oxygen from root nodules. It aids in...
Name any four growth hormones. Draw the chemical structure of auxin and gibberellins and describe the effects of both the hormones on plants
. Answer: Many hormones required for cell growth, such as auxins, gibberellins, brassinosteroids, ethylene, jasmonates, salicylic acid, strigolactones and cytokinins which able to accelerate or...
Name any two BT crops and also write the name of chief bacteria participating in their formation.
Answer: Bt Crops are transgenic plants that generate the same toxin as the Bacillus thuringiensis bacterium in the plant cell, protecting the plants from pests. The bacterium produces poisonous "cry...
What do you mean by diffraction of light?
The small bending of light as it passes around the edge of an object is known as diffraction. The degree of bending is determined by the wavelength of light's size in relation to the opening's size....
Describe the method of transplantation of disease resistant gene in a disease infected plant.
Answer: Plant disease resistance works in two ways to defend plants from pathogens: pre-formed structures and chemicals, and immune system responses triggered by infection. [MCC No. 1] Disease...
Explain the following: ii) Acid rain
Answer: Acid rain is any type of precipitation that contains acidic components, such as sulfuric or nitric acid, that falls to the earth in wet or dry form from the atmosphere. Because power plants,...
Explain the following: i) Biochemical oxygen demand
Answer: The amount of oxygen required by bacteria and other microorganisms while decomposing organic matter under aerobic (oxygen present) conditions at a specific temperature is referred to as...
Draw labelled diagrams only of different stages of development of dicot embryo
Establish the relation between critical angle and refractive index.
A refractive index is the ratio of the velocity of a light beam in the air to the velocities of the specified medium. The critical angle is inversely proportional to the refractive index, hence the...
Draw labelled diagram only of the transverse section of a mature anther.
What do you mean by mutual induction ?
Mutual induction is defined as a characteristic of coils that allows them to oppose current changes in another coil. When the current of one coil changes, the flow changes as well, causing EMF in...
What is the contribution of plants in balancing the environment?
Answer: They maintain ecological equilibrium by supplying living organisms with oxygen and absorbing carbon dioxide generated by them. Fire, which provides us with heat and food, requires oxygen as...
What is respiratory quotient? What will be the value of in organic acids and fat?
Answer. Because various energy pathways are used for lipids, carbs, and proteins, the respiratory quotient value reveals which macronutrients are being digested. The respiratory quotient for lipid...
Differentiate between cyclic and non- cyclic photophosphorylation.
Answer: Non-cyclic photophosphorylation occurs in both photosystems I and II, but cyclic photophosphorylation occurs exclusively in photosystem I. Only ATP is created in cyclic photophosphorylation,...
Single cell protein is obtained from which group of algae?
Answer: Algae as a source of SCP is a term which refers to either microscopic single-cell true algae or prokaryotic cyanobacteria, and their growth is based on use of carbon dioxide and light energy...
What is semiconductor?
Semiconductors have a unique set of electrical properties. A conductor is a substance that conducts electricity, while an insulator is a substance that does not conduct electricity.
In which plants do the stomata remain open during night and closed during the day?
Answer: In cactus stomata remains open during the night and closed during the day.
Photosynthesis process is found in which part of chlorophyll ?
Answer: Photosynthesis occurs in chloroplasts, which contain chlorophyll in plants. Chloroplasts have a double membrane around them and a third inner membrane called the thylakoid membrane that...
. Write one chief difference between active absorption and passive absorption.
Answer: The absorption of water by roots is known as active absorption. It is absorbed with the help of ATP in this procedure, whereas it is not absorbed with the help of ATP molecules in passive...
What is synandrous condition?
Answer: The fusion of both stamens or androecium with the filaments of the flower is known as synandrous condition.
What is the difference between magnification and magnifying power?
Guttation is usually found in i) Aquatic plants ii) Mesophytic plants iii) Xerophytic plants iv) Herbaceous plants.
Answer: ii) Mesophytic plants Explanation- Guttation refers to the exudation of xylem sap from the tips or margins of the leaves of some vascular plants, such as grasses, and fungi.
If other one or more genes are introduced in any plant, the plant will be called i) Transgressive ii) Transgenic iii) Triploid iv) Trisomic.
Answer: ii) Transgenic Explanation- Transgenic plants are plants into which one or more genes from another species have been introduced into the genome, using genetic engineering processes.
If concentration of increases continuously in the environment, what will be its effect? i) Ozone depletion. ii) Greenhouse effect iii) Increase in photorespiration iv) Suffocation.
Answer: i) Ozone depletion Explanation- Scientists warned forty years ago that a hole in the ozone layer encircling the earth might have major consequences for human health and the environment.
Double fertilization means i) the fusion of two male gametes with egg. , ii) one male gamete with the egg and the other with secondary nucleus. iii) one male gamete with the egg and other with synergid. iv) all of these.
Answer: iv) all of these Explanation- Flowering plants have a complex fertilisation feature called double fertilisation (angiosperms). One female gamete joins two male gametes throughout this...
What do you mean by inductive reactance?
The opposition offered by an inductor to the flow of alternating current through it is called the inductive reactance.
What do you mean by colour code of carbon resistance?
Resistors of many types and values are available commercially, but carbon resistors are more commonly employed in electronic circuits. The value of resistance in carbon resistors is denoted by four...
Write pathogenicity, symptoms and preventive measures of any two of the following diseases : iii) Dengue (break bone fever).
Answer: dengue, also called breakbone fever or dandy fever, acute infectious mosquito-borne fever that is temporarily incapacitating but rarely fatal. Besides fever, the disease is characterized by...
Write pathogenicity, symptoms and preventive measures of any two of the following diseases : ii) Elephantiasis
Answer: Elephantiasis is a tropical disease carried by parasitic worms transmitted by mosquito bites. The skin thickens and hardens, resembling that of an elephant. The following 3 types of...
Write pathogenicity, symptoms and preventive measures of any two of the following diseases : i) Malaria
Answer: Malaria can be contracted if you are bitten by a mosquito carrying the Plasmodium parasite. Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, and Plasmodium falciparum are the four...
What is electromagnetic wave ?
Electromagnetic waves, or EM waves, are waves that are formed when an electric field and a magnetic field vibrate together. EM waves, in other words, are made up of oscillating magnetic and electric...
What are ‘apiaries’ ? Describe with diagram the life cycle of Honeybee. Mention the economic importance of the product produced by them.
Answer: An apiary is a place where honey bees are kept in hives. Apiaries exist in all shapes and sizes, and depending on the honey production business, they can be rural or urban. An apiary can...
Write notes on any two of the following. iii) Semi-conservative method of DNA replication.
Answer: The mechanism of DNA replication in all known cells is known as semiconservative replication. Along the DNA template strand, DNA replication takes place at numerous sources. Replication...
Write Fleming’s left hand rule
When a current-carrying conductor is exposed to an external magnetic field, it is subjected to a force that is perpendicular to both the field and the current flow direction.
Write notes on any two of the following. ii) Sex-determination
Write notes on any two of the following. ii) Sex-determination Answer: The process of determining an organism's or offspring's sexual traits is known as sex determination. It assists in determining...
Write notes on any two of the following. i) Mendel’s Law of Independent Assortment
Answer: The alleles of two (or more) distinct genes are sorted into gametes independently of one another, according to Mendel's law of independent assortment. To put it another way, the allele a...
Describe the structure of DNA model proposed by James Watson and Francis Crick. Mention the differences between DNA and RNA.
Answer: The structure of DNA is a double-stranded, antiparallel, right-handed helix, as depicted in Watson and Crick's model. The outside of the helix is made up of the sugar-phosphate backbones of...
Defone wildlife. Give two main methods of their conservation.
Answer. Ex-situ and in-situ conservation, such as the establishment of National Parks, Sanctuaries, and Reserve Forests, can help to protect wildlife habitat. These protected area networks span the...
Write the names and functions of any two enzymes useful in genetic engineering.
Answer: The discovery of mainly two types of enzymes made genetic engineering possible: cutting enzymes called restriction endonucleases and joining enzymes called ligases. Ligase, on the other...
What are ‘transgenic animals’ ? Mention one principal method used for the production of transgenic animal.
Answer: Mice have been the principal species employed in the field of transgenics for practical reasons, such as their small size and low cost of housing in compared to larger vertebrates, their...
What is ‘gene therapy’ ? How does it differ from ‘enzyme therapy’
Answer: Gene therapy is a branch of medicine that focuses on modifying the genetic material of cells to achieve a therapeutic effect or to heal disease by repairing or reconstructing damaged genetic...
Write four uses of ‘Recombinant DNA Technology’ beneficial to human being.
Answer: It's also important in forensic science and archaeological genetic tests, as well as tests for establishing hereditary disease and paternity. Hepatitis and human immunodeficiency virus (HIV)...
Make a labelled diagram of Miller’s
Who propounded the theory of ‘Survival of the Fittest’ ? Explain this theory with example.
Answer . Herbert Spencer (1820–1903) was an English philosopher who initiated a philosophy called 'Social Darwinism'. He coined the term 'survival of the fittest' seven years before Darwin's...
What is mutation ? Write one example each of spontaneous and induced mutations.
Answer: A mutation occurs when the sequence of DNA changes. Mutations can occur as a result of DNA copying errors during cell division, exposure to ionising radiation, exposure to chemicals known as...
Write two differences between homologous and analogous organs and give two examples of each.
Answer: Homologous structures have the same embryonic origin, and homologous organs perform the same function. The bones of a whale's front flipper, for example, are very similar to the bones in a...
What is incomplete dominance? Explain it with example.
Answer: When none of a gene's factors are dominant, a heterozygous dominant individual's phenotype is a mix of dominant and recessive traits. Incomplete domination is the term for this situation....
What do you understand by ‘Biofertilizers’ ? Write the names of any two nitrogen fixing bacteria.
Answer: Rhizobium, Azotobacter, Azospirilium, and blue green algae (BGA) have long been used as biofertilizers. Leguminous crops benefit from Rhizobium inoculant. Wheat, maize, mustard, cotton,...
. Write full names of IUCN and WWF
Answer: IUCN, International Union for Conservation of Nature, World Wildlife Fund (WWF)
Define Hot spot. Write the names of two hot spots situated in India.
Answer: A territory must have lost at least 70% of its original natural vegetation to be recognised as a biodiversity hotspot, which is mainly due to human activity. The Himalayas, Western Ghats,...
Write two properties of diamagnetic substance.
1. In diamagnetic materials, there are no atomic dipoles since the resultant magnetic moment of each atom is zero due to paired electrons. 2. A magnet repels ferromagnetic materials.
A man with blood group marries a woman with blood group ‘AB’. What would be the blood group of their children ?
Answer: When a guy with blood group O marries a woman with blood group AB, the progeny with blood groups A and B means the male is homozygous. If a man is homozygous for the blood group O, his blood...