Class X

Biology questions

1. Which of the following adaptations in herbivores helps in digestions of cellulose?

A. Longer large intestine

B. Smaller large intestine

C. Smaller small intestine

D. Longer small intestine

2. There was a cerebellar dysfunction in a patient. Which of the following activities will
get disturbed in this patient as a result of this?

A. Salivation

B. Hunger control

C. Posture and balance

D. Regulation of blood pressure

3. In snails individuals can begin life as male and depending on environmental

conditions they can become female as they grow. This is because

A. male snails have dominant genetic makeup.

B. female snails have dominant genetic makeup.

C. expression of sex chromosomes can change in a snail’s life time.

D. sex is not genetically determined in snails.

4. Identify the incorrect statement ‘The energy available to the producers is maximum’
because:

A. It is the first trophic level which absorbs1% of light energy directly from the source.

B. It utilizes the most of the chemical energy for its own respiration, growth,
reproduction, movement etc.

C. It utilizes 10% of light energy and transfers the rest to the next trophic level.

D. It transfers only 10% of light energy to the next trophic level.

5. Which of the following is not a role of decomposers in the ecosystem?

A. Natural replenishment of soil.

B. Enrichment of oxygen in atmosphere.

C. Waste decomposition.

D. Break-down of dead remains.

6. Assertion (A): The number of chromosomes in a cell and in a germ cell is not the
same in any species.

Reason (R): When 2 germ cells combine they restore the normal number of
chromosomes in a species

7. Assertion (A): If the lions are removed from a food chain it will not affect the food
chain, however if the plants are removed from a food chain it will disturb the ecosystem.

Reason (R): Plants are producers who can make food using sunlight, while lions are
consumers.

8. List the steps for the synthesis of glucose by the plants. What special feature is
found in desert plants related to this process?

9. Explain the role of the following in the process of digestion of food in humans:

(i) Salivary amylase(ii) Pepsin(iii) Trypsin(iv) Lipase(V) Bile juice

10. The cartoon below addresses a growing concern:

What impact will the process shown in the image have on Humans if they occupy the
last trophic level? Explain.

11. Create a food chain with more than 2 trophic levels that exists in the cabbage farm.
If Humans occupy the last trophic level, then how would spraying pesticide affect the
humans? Explain.

12. Define-

Holozoic nutrition, respiration, excretion, circulation, peristaltic movement, Tropism,

Nastic movement , Alleles, Traits, Homozygous, Heterozygous , hemodialysis , double
circulation , transpiration , translocation , fermentation

13. Draw and label the diagrams of-

Stomata, Nutrition in amoeba, Digestive system, respiratory system, L.S./ vertical
section of human heart and brain, a neuron, a nephron , Reproductive system of male
and female, L.S. of a bisexual flower

14. Write a note on -

Opening and closing of stomata, urine formation, Inhalation and Exhalation, function of
epiglottis, gaseous exchange in lungs, feedback mechanism , major events occur during
photosynthesis, biological magnification

15. Explain all main types of Tropism with examples,write their stimulus also.

16. How , sex is determined? Explain with help of sex chromosomes for male and
female given below-

Male - XmY

Female - XfXf

How does sex determination in humans ,violates mendel's law of segregation?

17. Why did Mendel select pea plant for experiments? What were the seven contrasting
characters ,he work with?

18. Explain in short the working of Neurotransmitter, ADH.

19. Differentiate in between -

Arteries and veins, food chain and food web, biodegradable and non - biodegradable,
aerobic and an aerobic respiration , cerebrum and cerebellum , lymph and blood plasma,
self and cross pollination

20. Write hormones and their functions,produced and secreted by the endocrine glands
given below-

Hypothalamus, Pituitary, Thyroid, Thymus, Adrenal , Testes, Ovaries

21. Write main functions of - Auxin , Gibberellin ,absisic acid, cytokinins and ethylene

22. What is reflex action ? Draw reflex arc . Explain the mechanism of reflex action with
an example.

23. Describe, types of asexual reproduction. What is vegetative propagation?

24. Write importance of Tissue culture and Variation.

25. What will happen if -

I. Egg is fertilised .
II. Egg is not fertilised.

26. What are decomposers? List their few advantages.

27. What are STD's? Name them. Write their causes and symptoms.

28. Explain each of the Mendel's three laws of inheritance.

29. Why ,do herbivores have longer, small intestine than carnivores?

30. Write name and draw the diagram of the structure present in small intestine to
increase absorptive area. Why absorption of digested food occurs mainly in the small
intestine?

31. How would the pesticide affect the trophic levels in the following food chain
associated with a lake?

Plankton ->small fish. ->Large fish. -> Hawk

32. Given below is an image of an experiment conducted by a student to understand the

process of respiration. He blows into a clear solution present in the test tube and sees
that it turns cloudy.

I. What is the most likely substance present in the test tube?

Ii. What could be the aim of his experiment?

III. What kind of respiration is shown in the experiment? Justify your answer.

33. Explain the process of the breakdown of glucose by various pathways in a

comprehensive manner.

34. Write the role of insulin in regulating blood sugar levels in human body. Mention the
disease caused due to it.

35. Name the tropic movement and environmental stimulus required for-

Seed to develop downwords and shoot upwards , bending of shoot tip towards sunlight,
growing pollen tube towards ovules

36. I. What role do pituitary gland play in regulating the functions of reproductive glands?
II. Name three devices/ techniques used by human females to avoid pregnancy.
Mention the side effects caused by each. What is contraception?

37. Mendel crossed a pure tall pea plant (TT) with a pure short pea plant (tt) and
obtained all tall plants in F₁-generation.

(i) What is the gene combination present in the plants of F₁-generation?

(ii) Give reason why only tall plants are observed in F₁-progeny.

(iii) What will be the ratio of the plants obtained in the F₂-generation when F₁ plants are
self-pollinated?

38. I. Name and explain the two modes of asexual reproduction observed in Hydra.

39. In the given T.S. of a leaf , identify the layer of cells where maximum photosynthesis
occurs.

40. Write functions of the main parts of human brain.