ICSE Class 8 Biology Sample Paper with Solutions Set 03

Question 1

Choose the correct answer out of the four available choices given below each question. [15]

1. The leaves of _________ can give rise to a new plant. [1 Mark]
(a) Mango
(b) Bryophyllum
(c) Bougainvillea
(d) Rose

Answer: (b) Bryophyllum

Teacher's Note:
a) Bryophyllum reproduces vegetatively through leaf buds located on the margins.
b) Students often confuse vegetative propagation in leaves with stem cuttings.

2. The exocrine part of pancreas secretes___________. [1 Mark]
(a) Bile juice
(b) Pancreatic juice
(c) Gastric juice
(d) None of the above

Answer: (b) Pancreatic juice

Teacher's Note:
a) The exocrine pancreas releases pancreatic juice containing digestive enzymes into the small intestine.
b) Remember that the endocrine part of the pancreas secretes hormones like insulin and glucagon.

3. The heart is a muscular organ made up of __________ muscles. [1 Mark]
(a) Cardiac
(b) Skeletal
(c) Smooth
(d) Both 1 and 2

Answer: (a) Cardiac

Teacher's Note:
a) Cardiac muscles are specialized involuntary muscles found exclusively in the walls of the heart.
b) They never fatigue and work continuously throughout an organism's life.

4. Which of the following vaccines contains killed germs? [1 Mark]
(a) TAB vaccine for typhoid
(b) Salk’s vaccine for poliomyelitis
(c) Vaccine for rabies
(d) BCG vaccine for tuberculosis

Answer: (b) Salk’s vaccine for poliomyelitis (the marking scheme also accepts options (a) and (c) as vaccines containing killed germs, while BCG contains live weakened germs)

Teacher's Note:
a) Salk vaccine uses inactivated (killed) polioviruses to trigger an immune response safely.
b) BCG vaccine uses a live attenuated strain of Mycobacterium bovis.

5. Whooping cough is a/an _____________. [1 Mark]
(a) Droplet infection
(b) Food borne infection
(c) Air borne infection
(d) Water borne infection

Answer: (a) Droplet infection

Teacher's Note:
a) Whooping cough (pertussis) spreads via respiratory droplets released when an infected person coughs or sneezes.
b) Distinguish clearly between droplet infections and general airborne or waterborne diseases.

6. Reflex actions are under the control of the __________. [1 Mark]
(a) Brain
(b) Medulla oblongata
(c) Spinal cord
(d) Cerebellum

Answer: (c) Spinal cord

Teacher's Note:
a) Most reflex actions are processed rapidly through the spinal cord to bypass conscious brain thought for immediate protection.
b) Note that the brain is not directly involved in initiating the immediate reflex response.

7. Grass → ____________ → Tiger.
Which of the following best fits in the above food chain? [1 Mark]
(a) Deer
(b) Eagle
(c) Bacteria
(d) Lion

Answer: (a) Deer

Teacher's Note:
a) The missing link must be a primary consumer (herbivore) that feeds on grass and serves as prey for the tiger.
b) Eagles and lions do not feed directly on grass as herbivores.

8. The term ‘ecosystem’ is derived from the Greek word ‘oikos’ meaning [1 Mark]
(a) Body weight
(b) Food
(c) House
(d) Size

Answer: (c) House

Teacher's Note:
a) ‘Oikos’ in Greek translates to house or dwelling place.
b) Memorize etymological definitions as they frequently appear in objective type questions.

9. A butterfly in its development from larva to adult shows__________. [1 Mark]
(a) Fertilisation
(b) Metamorphosis
(c) Multiplication
(d) Both (1) and (2)

Answer: (b) Metamorphosis

Teacher's Note:
a) Metamorphosis is the biological process of transformation from an immature form to an adult form in distinct stages.
b) The stages in a butterfly include egg, larva, pupa, and adult.

10. Which of the following changes are not associated with adolescence? [1 Mark]
(a) Change in body shape
(b) Change in voice
(c) Increase in height
(d) Decreased activity of sweat and sebaceous glands

Answer: (d) Decreased activity of sweat and sebaceous glands

Teacher's Note:
a) During adolescence, the activity of sweat and sebaceous (oil) glands actually increases, often causing acne.
b) Read options carefully to spot negative phrasing like ‘not associated’.

11. The technique of crossing two individuals of different varieties is called__________. [1 Mark]
(a) Tissue culture
(b) Self pollination
(c) Cross pollination
(d) Hybridisation

Answer: (d) Hybridisation

Teacher's Note:
a) Hybridisation combines desirable characters from two different genetic varieties.
b) Do not confuse hybridisation with general cross-pollination, which can occur naturally between plants of the same species.

12. Which one of the following favours the fastest transpiration rate? [1 Mark]
(a) A cool, humid, windy day
(b) A hot, humid, windy day
(c) A hot, humid, still day
(d) A hot, dry, windy day

Answer: (d) A hot, dry, windy day

Teacher's Note:
a) High temperature, low humidity (dryness), and wind speed all increase the rate of evaporation and transpiration.
b) High humidity decreases transpiration because the surrounding air is already saturated with moisture.

13. ____________________ is a cross-breed cow milch species. [1 Mark]
(a) Red sindhi
(b) Karan swiss
(c) Jersey
(d) Sahiwal

Answer: (b) Karan swiss

Teacher's Note:
a) Karan Swiss is a cross-breed developed specifically for high milk yield.
b) Red Sindhi and Sahiwal are indigenous (local) breeds, while Jersey is an exotic breed.

14. The absence or low number of clotting factors results in a rare condition called_______. [1 Mark]
(a) Anaemia
(b) Sickle cell anaemia
(c) Haemophilia
(d) Filaria

Answer: (c) Haemophilia

Teacher's Note:
a) Haemophilia is a genetic bleeding disorder where blood fails to clot normally due to missing clotting factors.
b) Anaemia relates to a deficiency of red blood cells or hemoglobin, not clotting factors.

15. Marasmus is caused due to lack of ________. [1 Mark]
(a) Carbohydrates
(b) Proteins
(c) Fats
(d) Both (1) and (2)

Answer: (d) Both (1) and (2)

Teacher's Note:
a) Marasmus is a form of severe protein-energy malnutrition caused by a deficiency of both proteins and total calories (carbohydrates).
b) Kwashiorkor is primarily caused by protein deficiency alone, whereas marasmus involves overall energy starvation.

Question 2

(A) Mention the food constituent which may be lacking in ones diet, in case of the following: [5 Marks]

1. A child having rickets [1 Mark]

Answer: Vitamin D

Teacher's Note:
a) Vitamin D helps in the absorption of calcium for bone mineralization.
b) Deficiency leads to soft, weak bones characteristic of rickets.

2. A person suffering from scurvy [1 Mark]

Answer: Vitamin C

Teacher's Note:
a) Vitamin C (ascorbic acid) is essential for collagen synthesis.
b) Scurvy is characterized by bleeding gums and poor wound healing.

3. A person suffering from beri-beri [1 Mark]

Answer: Vitamin B₁

Teacher's Note:
a) Vitamin B₁ is also known as thiamine.
b) Beri-beri affects the peripheral nervous system and cardiovascular system.

4. A child suffering from kwashiorkor [1 Mark]

Answer: Proteins

Teacher's Note:
a) Kwashiorkor occurs when a child's diet lacks adequate protein despite having sufficient carbohydrate intake.
b) Symptoms include edema, swollen belly, and retarded growth.

5. A person suffering from anaemia [1 Mark]

Answer: Iron

Teacher's Note:
a) Iron is a vital component required for hemoglobin formation in red blood cells.
b) Iron deficiency reduces the oxygen-carrying capacity of the blood, causing fatigue.

(B) Fill in the blanks and rewrite the sentences: [5 Marks]

1. Reproduction in spirogyra is by means of ________________. [1 Mark]

Answer: Reproduction in spirogyra is by means of fragmentation.

Teacher's Note:
a) Spirogyra is a filamentous alga that breaks into pieces, each growing into a new filament.
b) Ensure the full sentence is rewritten as instructed in the question.

2. The colourless fluid that flows within the lymphatic system is called ___________. [1 Mark]

Answer: The colourless fluid that flows within the lymphatic system is called lymph.

Teacher's Note:
a) Lymph lacks red blood cells and platelets, containing mainly white blood cells.
b) It plays a crucial role in body defense and fat absorption.

3. Kwashiorkor is caused due to the deficiency of _____________. [1 Mark]

Answer: Kwashiorkor is caused due to the deficiency of proteins.

Answer: Interstitial cells produce testosterone.

Teacher's Note:
a) Interstitial cells (also called Leydig cells) are located adjacent to the seminiferous tubules in the testes.
b) They secrete the primary male sex hormone, testosterone.

5. The period of life when the body undergoes development leading to reproductive maturity is called ______________. [1 Mark]

Answer: The period of life when the body undergoes development leading to reproductive maturity is called adolescence.

Teacher's Note:
a) Adolescence is a transitional phase of physical and mental human development.
b) Puberty marks the specific onset of reproductive maturity within adolescence.

Question 3

(A) Match the items in column I with the appropriate items in column II. [5 Marks]

Answer:
1. Diabetes - c) insulin
2. Bread mould - e) spores
3. Ovaries - a) oestrogen
4. Active transport - b) uses energy
5. Plasma - d) liquid component of blood

Teacher's Note:
a) Match items accurately by writing the complete pair to avoid scoring errors.
b) Active transport requires cellular energy (ATP) to move molecules against a concentration gradient.

(B) Study the diagram below and answer the questions that follow: [5 Marks]

[Figure: Diagram of the human endocrine system showing Pineal Gland, Pituitary Gland, Thyroid, Thymus, Pancreas, Ovary, and Testis, along with an inset pointing to the adrenal glands above the kidneys.]

1. Name the gland above the kidney? [1 Mark]

Answer: Adrenal gland

Teacher's Note:
a) Adrenal glands sit directly on top of each kidney.
b) They secrete hormones like adrenaline to help the body cope with stress.

2. Name two glands that are associated with the digestive system through their secretions? (endocrine glands) [1 Mark]

Answer: Pancreas and thyroid gland (Note: The official key lists Pancreas and thyroid gland based on question grouping)

Teacher's Note:
a) The pancreas has both exocrine digestive functions and endocrine hormone-secreting functions.
b) Read parenthetical notes carefully as they guide the expected answer category.

3. Which hormone is made up of iodine? [1 Mark]

Answer: Thyroxine

Teacher's Note:
a) Iodine is an essential raw material required by the thyroid gland to synthesize thyroxine.
b) Iodine deficiency causes goiter.

4. What is a mixed gland? Give an example? [2 Marks]

Answer:
1. A gland which has both exocrine and endocrine properties is known as a mixed gland.
2. Example: Pancreas.

Teacher's Note:
a) Mixed glands release secretions through ducts (exocrine) and directly into the bloodstream (endocrine).
b) Always provide both definition and a valid example for full credit.

Question 4

(A) [5 Marks]

[Figure: Diagram of a flower showing parts labelled A (Stigma), B (Style), C (Ovary), and D (Corolla/Petals) with ovule inside the ovary.]

i. Name the parts A, B, C and D. [2 Marks]

Answer:
A - Stigma
B - Style
C - Ovary
D - Corolla (Petals)

Teacher's Note:
a) A, B, and C together constitute the female reproductive organ of the flower (pistil or carpel).
b) D represents the colorful petals that attract pollinators.

ii. State the function of part A. [3 Marks]

Answer: It is a disc-shaped structure, which receives the pollen during pollination.

Teacher's Note:
a) The sticky surface of the stigma traps pollen grains effectively.
b) It initiates the germination of pollen grains to form the pollen tube.

(B) Draw a neat diagram of the following and only, label the parts mentioned against it. [5 Marks]

1. Nerve cell [2½ Marks]

Answer:
[Figure: Diagram of a multipolar neuron showing Dendrites, Cell body, Nucleus, Axon, Direction of impulse, and Axon terminals.]

Teacher's Note:
a) Draw clear sketches with neat pencil lines and precise labels pointing to exact structures.
b) Indicate the direction of nerve impulse flow clearly using an arrow along the axon.

2. Section of artery and vein [2½ Marks]

Answer:
[Figure: Cross-sectional diagram comparing an artery (thick muscular wall, narrow lumen) and a vein (thin muscular wall, wide lumen).]

Teacher's Note:
a) Highlight the thick muscular wall and narrow lumen for arteries.
b) Show the thin muscular wall and wide lumen for veins.

Question 5

(A) Give one point of difference between the following on the basis of what is given in the brackets: [5 Marks]

1. Fragmentation and regeneration (process) [1 Mark]

Answer:

Teacher's Note:
a) Fragmentation is a normal mode of asexual reproduction through body splitting.
b) Regeneration often acts as a repair mechanism that can also result in whole-organism reproduction.

2. Endocrine glands and exocrine glands (secretions) [1 Mark]

Answer:

Teacher's Note:
a) Endocrine glands are ductless glands.
b) Exocrine glands possess specific ducts for transporting their secretions.

3. Artery and vein (muscular wall) [1 Mark]

Answer:

Teacher's Note:
a) Arteries withstand high pressure from blood pumped directly by the heart.
b) Veins carry blood under lower pressure back towards the heart.

4. Kharif crops and rabi crops (season of cultivation) [1 Mark]

Answer:

Teacher's Note:
a) Kharif crops depend heavily on monsoon rains.
b) Rabi crops are winter-season crops requiring cooler cultivation temperatures.

5. Xylem and phloem (substances transported) [1 Mark]

Answer:

Teacher's Note:
a) Xylem transport is primarily unidirectional (roots to leaves).
b) Phloem transport is bidirectional to supply nutrients wherever needed.

(B) Complete the correlation. [5 Marks]

1. Fresh water fish: Tilapia:: ________________________: Marine water fish [1 Mark]

Answer: Bombay duck

Teacher's Note:
a) Tilapia is a well-known freshwater fish species.
b) Bombay duck (Harpadon nehereus) is a prominent marine water fish.

2. Millets: cereals:: Hemp: ________________________ [1 Mark]

Answer: Fibre yielding crop

Teacher's Note:
a) Millets belong to the category of cereals.
b) Hemp is cultivated primarily as a fibre-yielding crop.

3. Bombyx mori: Sericulture:: Apiculture: _____________________ [1 Mark]

Answer: Apis indica (or Honey bees)

Teacher's Note:
a) Bombyx mori is the silkworm reared in sericulture.
b) Apiculture is the rearing of honey bees (such as Apis indica).

4. Fry: Nursery tank:: Rearing tank: _______________________ [1 Mark]

Answer: Fingerling

Teacher's Note:
a) Fish fry are kept in nursery tanks during early development.
b) As they grow into fingerlings, they are transferred to rearing tanks.

5. Fowl Pox: Ranikhet:: ____________________: Bacterial disease [1 Mark]

Answer: Coryza (or Fowl cholera)

Teacher's Note:
a) Fowl pox and Ranikhet are common viral diseases in poultry.
b) Infectious coryza is a common bacterial disease affecting poultry.

Question 6

(A) What is a reflex arc? Answer the following in the correct sequence: [5 Marks]

Answer:
Reflex arc: The path which is travelled by the impulse during a reflex action is called a reflex arc.
The correct sequence is:
2. A receptor receives a stimulus.
1. A sensory neuron conducts the impulse from the receptor to the spinal cord.
4. An association neuron transmits the impulse from the sensory neuron to a motor neuron.
3. The motor neuron passes the impulse to an effector, which carries out the action in response to the stimulus.

Teacher's Note:
a) A reflex arc maps the exact neurological pathway of a reflex action.
b) Memorize the sequence starting from receptor detection to effector response.

(B) Define the following terms: [5 Marks]

1. Gestation period [1 Mark]

Answer: It is the period of development of the embryo inside the uterus.

Teacher's Note:
a) Gestation spans from fertilization until birth.
b) Duration varies across different animal species.

2. Diffusion [1 Mark]

Answer: Diffusion is the free movement of molecules of a substance from a region of its higher concentration to a region of its lower concentration, until the concentration in both regions is equal.

Teacher's Note:
a) Diffusion is a passive transport process requiring no cellular energy.
b) It is essential for gas exchange in living cells.

3. Apiculture [1 Mark]

Answer: It is the artificial rearing of honey bees or the maintenance of colonies of honey bees by humans to obtain honey and other commercially important products.

Teacher's Note:
a) Apiculture yields honey and beeswax.
b) It also aids significantly in agricultural crop pollination.

4. Blood transfusion [1 Mark]

Answer: It is the transfer of blood from one person to another person.

Teacher's Note:
a) Blood grouping (ABO system and Rh factor) must be matched prior to transfusion.
b) It is vital for replacing blood lost due to injury or surgery.

5. Ecosystem [1 Mark]

Answer: It is a self-contained area composed of all different living organisms living in it, interacting with each other as well as with the physical conditions such as sunlight, soil, water, climatic factors, etc. prevailing in the area.

Teacher's Note:
a) An ecosystem consists of biotic (living) and abiotic (non-living) components.
b) Energy flow and nutrient cycling are key functional aspects of any ecosystem.

Question 7

(A)

1. Give scientific reasons: [3 Marks]

(a) Adolescents need to plan their diet and lifestyle to maintain a healthy body. [1 Mark]

Answer: It is important to eat the right kind of food while growing. This helps the bones, muscles and other parts of the body to get enough nourishment for their growth. Hence, adolescents need to plan their diet and lifestyle to maintain a healthy body.

Teacher's Note:
a) Rapid physical growth and hormonal changes during adolescence increase nutritional requirements.
b) Balanced diets prevent nutritional deficiencies and promote long-term health.

(b) Yeast is used in bakery products. [1 Mark]

Answer: Yeasts undergo anaerobic fermentation and produce carbon dioxide and ethyl alcohol. The formation of carbon dioxide raises the bread dough or cakes. They also multiply very fast. Therefore, yeast is used in bakery products.

Teacher's Note:
a) Anaerobic respiration by yeast releases carbon dioxide gas.
b) Trapped gas bubbles cause dough to rise, giving baked goods a soft texture.

(c) The scrotum lies outside the body cavity. [1 Mark]

Answer: Sperms, for their survival, require a lower temperature. Since the scrotum is outside the body it maintains a suitable temperature for the testes, which is 2 to 3 degrees Celsius below the body temperature. Therefore, the scrotum containing the testes lies outside the body cavity.

Teacher's Note:
a) Normal core body temperature is too high for viable sperm production.
b) External location ensures optimal spermatogenesis.

2. A man was suffering from diabetes. He was urinating frequently in copious amounts resulting in loss of water. Which type of diabetes is this and which hormone is responsible for it? [2 Marks]

Answer:
1. This is diabetes insipidus.
2. It is caused due to a deficiency of the anti-diuretic hormone (ADH).

Teacher's Note:
a) Distinguish between diabetes mellitus (insulin deficiency) and diabetes insipidus (ADH deficiency).
b) ADH promotes water reabsorption in the kidneys, preventing excessive water loss.

(B)

1. What is a food pyramid? What is the role of food pyramid in the functioning of ecosystems? [3 Marks]

Answer:
1. A graphical representation of various trophic levels of a food chain in an ecosystem is called an ecological pyramid or a food pyramid.
2. Role of food pyramid in the functioning of ecosystems:
- The trophic levels in a food chain can be explained with the help of a food pyramid.
- The ecological pyramids help us to understand the structure, functional diversity and energy conversion efficiency of ecosystems.

Teacher's Note:
a) Food pyramids typically place producers at the base and apex predators at the top.
b) They demonstrate the progressive loss of energy at each successive trophic level according to the ten percent law.

2. Explain the method of asexual reproduction in plants by any one sub-aerial stem. (Draw a diagram if necessary). [2 Marks]

Answer:
1. Offset is a shoot emerging from a bud on the main stem. As it grows, it falls off from the main bud and grows into an independent plant.
2. This is an example of asexual reproduction in plants by sub-aerial stem (e.g., Water hyacinth).

[Figure: Diagram of an offset showing horizontal runner connecting two plantlets with roots growing downwards in water.]

Teacher's Note:
a) Sub-aerial stems grow horizontally above or just below the ground surface.
b) Mentioning examples like runner, stolon, or offset strengthens the answer.