Solved Sample Paper 3

Section A

Question 1(i)

The duration for which the leaf is kept in dark to get destarch is

1. 20-24 hrs
2. 24-48 hrs
3. 12-24 hrs
4. 12-42 hrs

Answer

24-48 hrs

Reason — The starch present in leaves is converted to soluble sugar at night and is then transported to different parts of the plant. This process takes 24-48 hrs.

Question 1(ii)

Vasectomy is

1. indirect measure to control population
2. educational measure to control population
3. national policy to control population
4. direct measure to control population

Answer

direct measure to control population

Reason — As vasectomy is a surgical contraception method for males, so it is a direct measure to control population.

Question 1(iii)

The blood cells produced abnormally in leukemia are

1. RBCs
2. WBCs
3. Both (1) and (2)
4. None of these

Answer

WBCs

Reason — Leukemia is a cancer of the tissue forming WBCs whose number increases manifold at the cost of RBCs.

Question 1(iv)

The location, where human sperm maturation takes place is

1. prostate gland
2. leydig cells
3. seminiferous tubules
4. epididymis

Answer

epididymis

Reason — The epididymis stores the sperms for some days during which they mature and become motile (capable of moving).

Question 1(v)

The blood cells involved in the process of oxygen transport are

1. lymphocytes
2. monocytes
3. erythrocytes
4. thrombocytes

Answer

erythrocytes

Reason — Erythrocytes have oxygen carrying haemoglobin, which transports oxygen to all body parts.

Question 1(vi)

Assertion (A): Hypersecretion of adrenal cortex causes Cushing's syndrome.

Reason (R): Symptoms of Cushing's syndrome are obesity, hyperglycemia, weakness, osteoporosis, salt and water retention.

1. Both A and R are true
2. Both A and R are false
3. A is true and R is false
4. A is false and R is true

Answer

Both A and R are true

Reason — Hypersecretion of cortisone from adrenal gland causes Cushing's syndrome. Symptoms are obesity, hyperglycemia (high blood sugar), weakness, osteoporosis, salt and water retention.

Question 1(vii)

Which of the following vitamin is essential for the production of prothrombin?

1. Vitamin-E
2. Vitamin-K
3. Vitamin-C
4. Vitamin-A

Answer

Vitamin-K

Reason — Vitamin-K is essential for production of prothrombin which helps in clotting of blood

Question 1(viii)

Prakash is a resident of hilly region where iodine is deficient in soil and hence in the food grown there. He started developing swelling in the neck. This was due to

1. simple goitre
2. cretinism
3. myxoedema
4. exophthalmic goitre

Answer

simple goitre

Reason — Simple Goitre is caused due to deficiency of thyroxine in food.

Question 1(ix)

The condition affecting the older people who cannot see nearby objects clearly is called

1. presbyopia
2. cataract
3. astigmatism
4. hyperopia

Answer

presbyopia

Reason — In presbyopia, the lens loses flexibility resulting in a kind of far-sightedness.

Question 1(x)

The cellular elements found in highest number in blood are

1. RBCs
2. lymphocyte
3. eosinophils
4. basophils

Answer

RBCs

Reason — RBCs are most numerous in blood. Each cubic millimeter of blood contains 4-6 million RBCs.

Question 1(xi)

The difference between the birth rate and the death rate is called

1. natality
2. mortality
3. growth rate of population
4. population density

Answer

growth rate of population

Reason — The difference between the birth rate and the death rate of a country is called the growth rate of the population.

Question 1(xii)

Which phytohormone have specific effects on cell division?

1. Ethylene
2. Gibberellins
3. Cytokinin
4. Auxin

Answer

Cytokinin

Reason — Cytokinin is known for stimulating plant growth by cell division.

Question 1(xiii)

Transpiration is highest during the summer. Which of the following reasons supports this statement?

P. Increase in temperature allows more water to evaporate.

Q. Warm air can hold more water than cold air.

R. Increase in temperature allows less water to evaporate.

1. Only P
2. Only R
3. Only P and Q
4. Only Q and R

Answer

Only P and Q

Reason — Transpiration is highest during the summer because higher temperature allows more evaporation and also warm air has more moisture holding capacity.

Question 1(xiv)

The cones contain the pigment

1. rhodopsin
2. visual purple
3. iodopsin
4. Both 1 and 2

Answer

iodopsin

Reason — Iodopsin is present in cone cells and is responsible for colour vision.

Question 1(xv)

Rajeev developed a clot at the site of bleeding. Which of the following is/are involved in the process described above?

(1) Platelets
(2) WBCs
(3) Plasma
(4) RBCs

1. Only 1
2. only 1 and 2
3. Only 1, 3 and 4
4. Only 1, 2 and 4

Answer

Only 1

Reason — Clotting is initiated by release of thrombokinase by disintegrating platelets.

Question 2(i)

Name the following:

(a) The centre of reflex action.

(b) A gas responsible for greenhouse effect.

(c) The site, where the sperm and ovum unite and fuse.

(d) The cytoplasmic division of a cell.

(e) The phase of cardiac cycle, in which the auricles contract.

Answer

(a) Spinal cord

(b) CO₂

(c) Fallopian tube

(d) Cytokinesis

(e) Atrial systole

Question 2(ii)

Arrange and rewrite the terms in each group in correct order so as to be in a logical sequence beginning with the term that is underlined.

(a) Chloroplast, Thylakoids, Grana, Stroma

(b) Urinary bladder, Kidney, Urethra, Ureter

(c) Conjunctiva, Retina, Cornea, Optic nerve, lens

(d) Repolarisation, Depolarisation, Resting potential

(e) Axial filament, Acrosome, Nucleus, Tail, Middle piece

Answer

(a) Chloroplast, Stroma, Grana, Thylakoids

(b) Kidney, Ureter, Urinary bladder, Urethra

(c) Conjunctiva, Cornea, Lens, Retina, Optic nerve

(d) Resting potential, Depolarisation, Repolarisation.

(e) Acrosome, Nucleus, Middle piece, Axial filament, Tail.

Question 2(iii)

Fill in the blanks with suitable words.

Spleen is the largest (a) ............... , it acts as (b) ............... , produces (c) ............... destroys worn out (d) ............... and produces RBCs in (e) ............... .

Answer

Spleen is the largest (a) lymphatic organ, it acts as (b) blood reservoir, produces (c) lymphocytes, destroys worn out (d) RBCs and produces RBCs in (e) embryo.

Question 2(iv)

Choose the odd one out from the following terms and name the category to which the other belong.

(a) Sneezing, Coughing, Typing, Blinking

(b) Goitre, Dwarfism, Acromegaly, Cataract

(c) Sewage, Radiation, Oil spills, Thermal pollution

(d) ADH, TSH, NADP, ACTH

(e) Colour blindness, AIDS, Haemophilia, Albinism

Answer

(a) Odd one: Typing
Category: Others are Natural reflexes

(b) Odd one: Cataract
Category: Others are Diseases due to hormonal imbalance.

(c) Odd one: Radiation
Category: Others are Water pollution

(d) Odd one: NADP
Category: Others are Hormones

(e) Odd one: AIDS
Category: Others are Genetic diseases

Question 2(v)

Match the items given in Column I with the most appropriate ones in Column II and rewrite the correct matching pairs.

Answer

Section B

Question 3(i)

Define nucleosomes.

Answer

DNA surrounds a core of 8 Histones to form a unit called nucleosome. These nucleosomes coil to form chromatin fibres.

Question 3(ii)

State the function of motor neuron and draw the path of reflex arc.

Answer

Motor neurons carry impulse from brain and spinal cord to effector organs.

Question 3(iii)

In a certain species of animals, black fur (B) is dominant over brown fur (b). Predict a genotype and phenotype of the offspring, when both parents are Bb or have heterozygous black fur.

Answer

In the question it is given that B refers to black fur and b refers to brown fur. So the genotype and phenotype of the offspring will be:

Genotype — 1 (Homozygous Black Fur) : 2 (Heterozygous Black Fur) : 1 (Homozygous Brown Fur)

Phenotype — 3 (Black Fur): 1 (Brown Fur)

Question 3(iv)

Differentiate between grana and stroma.

Answer

Differences between grana and stroma are:

Question 3(v)

Draw a neat and labelled diagram showing the relationship of artery, capillaries and vein.

Answer

Diagram showing the relationship of artery, capillaries and vein is shown below:

Question 4(i)

Mention the exact location of Adrenal gland.

Answer

Adrenal glands are present as a cap on the top of each kidney.

Question 4(ii)

What are the functions of adrenaline - the emergency hormone?

Answer

Adrenaline causes stimulation of sympathetic nervous system and prepares body for any emergency. It increases heart beat and blood supply to muscles.

Question 4(iii)

Differentiate between fibrin and fibrinogen.

Answer

Question 4(iv)

Which gland secretes vasopressin? What is its effect on body?

Answer

Posterior pituitary gland secretes vasopressin. Its effects on the body are:

1. It acts on the kidney increasing reabsorption of water from the kidneys tubules.
2. It constricts blood vessels causing rise in blood pressure.

Question 4(v)

Draw a neat and labelled diagram of human sperm.

Answer

Labelled diagram of a human sperm is shown below:

Question 5(i)

Define global warming.

Answer

The rise in average mean temperature of the Earth on account of enhanced concentration of greenhouse gases in the atmosphere is known as global warming.

Question 5(ii)

Why light reaction is also called the photochemical phase?

Answer

Light reaction is also called the photochemical phase because it is light dependent reaction. The chlorophyll on exposure to light energy becomes activated by absorbing photons. The absorbed energy is used in splitting the water molecule (H₂O) into its two components (Hydrogen and Oxygen) and releasing electrons.

Question 5(iii)

Soil pollution leads to the accumulation of pesticides in birds. This affects calcium metabolism in them. What will be the effect of this on their egg shells?

Answer

Birds affected by pesticide accumulation may produce eggs with thinner, weaker shells. The eggshells may also have structural abnormalities and defects. Such fragile egg shells may break before hatching of the eggs leading to population decline and eventual extinction of the affected birds.

Question 5(iv)

Number of live births per 1000 people of population per year is A while the number of deaths per 1000 people of population per year is B. Name A and B.

Answer

A → Natality

B → Mortality

Question 5(v)

The diagram given below is of Malpighian capsule. Answer the questions that follows.

(a) Name the parts labelled 1, 2 and 3.

(b) Define ultrafiltration.

(c) Name the fluid entering the renal tubule.

Answer

(a) Parts labelled 1, 2 and 3 are:

• 1 → Afferent arteriole
• 2 → Efferent arteriole
• 3 → Bowman's capsule

(b) The blood flows through the glomerulus under great pressure which is much greater than in the capillaries elsewhere. The high pressure causes the liquid part of the blood to filter out from the glomerulus into the renal tubule. This filtration under extraordinary force is called Ultrafiltration.

(c) Glomerular filtrate

Question 6(i)

Give the exact location of Zona pellucida.

Answer

Zona pellucida surrounds the plasma membrane of oocyte.

Question 6(ii)

Differentiate between mitosis and meiosis with reference to the type of cells in which they occur.

Answer

Mitosis occurs in somatic cells whereas Meiosis occurs in reproductive cells.

Question 6(iii)

Explain the term root pressure.

Answer

The upward flow of water due to heavy pressure from the roots is called root pressure. The pressure developed in roots is due to the continuous inflow of water which pushes the plant sap upwards. Thus, it is one of the forces to raise water up through the stem into the leaves.

Question 6(iv)

The possibility of a female becoming haemophilic is extremely rare. Justify.

Answer

Haemophilia is an X-linked recessive genetic disorder caused by mutations in genes located on the X chromosome. Since females typically inherit two X chromosomes, the chance of both X chromosomes carrying the recessive mutation is indeed rare. Therefore, the likelihood of a female developing hemophilia is extremely low.

Question 6(v)

Study the given diagram below and answer the questions that follows.

(a) Name the parts labelled A to D.

(b) Which type of blood flows through B?

(c) State the function of the part labelled E.

Answer

(a) The parts labelled A to D are:

• A → Pulmonary artery
• B → Aorta
• C → Bicuspid (Mitral) valve
• D → Left atrium

(b) Oxygenated blood flows through aorta.

(c) E represents right atrium. It receives deoxygenated blood from all parts of the body.

Question 7(i)

What is the symbol of family welfare in India?

Answer

An inverted red triangle is the symbol of family welfare in India.

Question 7(ii)

Give differences between Stomata and Lenticels.

Answer

Differences between Stomata and Lenticels are:

Question 7(iii)

What is tropism? Give one example.

Answer

Growth movements occurring in plants in response to unidirectional external stimuli is called tropism. For example, in phototropism plants tend to grow towards light.

Question 7(iv)

What are the main objective of family welfare programme?

Answer

The main objective of family welfare programme are:

1. Family planning in terms of having a small family.
2. Total welfare of the small family, including the diet and nutrition of the child and pregnant mother.
3. Subsequent care of the children, like immunisation and oral rehydration therapy, to ensure survival of the young ones

Question 7(v)

Study the diagram and answer the questions that follows.

(a) Identify the experiment to be performed with this leaf.

(b) What will you observe if starch test is performed on this leaf?

(c) What does the experiment signify?

Answer

(a) The above experiment is used to prove that the chlorophyll is necessary for photosynthesis.

(b) When we test the leaf for starch, we observed that only the areas of leaf which were green (i.e. contains chlorophyll) turned blue-black showing the presence of starch.

(c) The experiment proves that photosynthesis can occur only in the presence of chlorophyll.

Question 8(i)

Define osmoregulation.

Answer

The process of maintaining or regulating the water and salt concentration in the body is called osmoregulation.

Question 8(ii)

Write the full form of MTP. In what circumstances is it recommended?

Answer

MTP stands for Medical Termination of Pregnancy.

It is recommended in case of serious genetic disease or if the couple does not want to have the child. It is only permitted within 6 months of pregnancy.

Question 8(iii)

Rapidly growing industries favoured population rise. Explain by giving suitable reasons.

Answer

Rapidly growing industries increased the national wealth, raised the standard of living and made life more comfortable. More job opportunities, ample resources and food availability are the factors that favoured population rise.

Question 8(iv)

Write the different stages of human ancestors during evolution.

Answer

Ramapithecus → Australopithecus → Homo habilis → Homo erectus → Neanderthal man → Cro-Magnon → Homo sapiens sapiens (Modern man).

Question 8(v)

Study the diagram given below and answer the following questions.

(a) Identify the stage of mitosis shown in the above diagram.

(b) Name the parts labelled A, B, C and D.

(c) Differentiate between mitosis and meiosis based on their occurrence.

Answer

(a) Metaphase.

(b) Parts A to D are:

• A → Chromatin
• B → Mitotic spindle
• C → Aster
• D → Centromere

(c) Mitosis occurs in somatic cells whereas Meiosis occurs in reproductive cells or gamete forming cells.