Nervous system mechanism	Hormonal system mechanism
1. The information is conveyed in the form of electric impulse.	1. The information is conveyed in the form of chemical messengers.
2. The axons and dendrites transmit the information through a coordinated effort.	2. The information is transmitted or transported through blood.
3. The flow of information is rapid and the response is quick.	3. The information travels slowly and the response is slow.
4. Its effects are short lived.	4. It has prolonged effects.

Movement in sensitive plants	Movement in our legs
1. The movementthat takes place in a sensitive plant such as Mimosa pudica occurs in response to touch (stimulus).	1. Movement in our legs is an example of voluntary actions..
2. For this movement, the information is transmitted from cell to cell by electro-chemical signals as plants do not have any specialised tissue for conduction of impulses.	2. The signal or messages for these actions are passed to the brain and hence are consciously controlled.
3. For this movement to occur, the plant cells change shape by changing the amount of water in them.	3. In animal muscle cells, some proteins are found which allow the movement to occur.

1. Which of the following statements is correct about receptors?
(a) Gustatory receptors detect taste while olfactory receptors detect smell
(b) Both gustatory and olfactory receptors detect smell
(c) Auditory receptors detect smell and olfactory receptors detect taste
(d) Olfactory receptors detect taste and gustatory receptors smell
Ans. (a) Gustatory receptors detect taste while olfactory receptors detect smell
2. Electrical impulse travels in a neuron from
(a) Dendrite→ axon →axonal end →cell body
(b) Cell body →dendrite →axon →axonal end
(c) Dendrite →cell body →axon →axonal end
(d) Axonal end →axon →cell body →dendrite
Ans. (c) Dendrite→ cell body→ axon →axonal end
Explanation: Dendrites of a neuron receive electrical impulse from axonal end of another neuron. After that, electrical impulse travels through cell body, axon; to the axonal end.

3. In a synapse, chemical signal is transmitted from
(a) dendritic end of one neuron to axonal end of another neuron
(b) axon to cell body of the same neuron
(c) cell body to axonal end of the same neuron
(d) axonal end of one neuron to dendritic end of another neuron
Ans. (d) axonal end of one neuron to dendritic end of another neuron 
Explanation: Refer to previous question’s explanation.

4. In a neuron, conversion of electrical signal to a chemical signal occurs at/in
(a) cell body
(b) axonal end
(c) dendritic end
(d) axon
Ans. (b) Axonal end
Explanation: At the axonal end, electrical impulse sets off the release of some chemicals; called neurotransmitters. These chemicals enter the dendrite of another neuron to transmit the signal.

5. Which is the correct sequence of the components of a reflex arc?
(a) Receptors→ Muscles→ Sensory neuron→ Motor neuron→ Spinal cord
(b) Receptors→ Motor neuron →Spinal cord →Sensory neuron →Muscle
(c) Receptors →Spinal cord →Sensory neuron →Motor neuron →Muscle
(d) Receptors →Sensory neuron →Spinal cord →Motor neuron →Muscle
Ans. (d) Receptors →Sensory neuron →Spinal cord →Motor neuron →Muscle  

Explanation: In a reflex arc, sensory neurons pick signals from receptors. These signals are then sent to the spinal cord; from where they go to muscle via motor neuron.

6. Which of the following statements are true?
(i) Sudden action in response to something in the environment is called reflex action
(ii) Sensory neurons carry signals from spinal cord to muscles
(iii) Motor neurons carry signals from receptors to spinal cord
(iv) The path through which signals are transmitted from a receptor to a muscle or a
gland is called reflex arc
(a) (i) and (ii)
(b) (i) and (iii)
(c) (i) and (iv)
(d) (i), (ii) and (iii)
Ans. (c) (i) and (iv)
Explanation: Sensory neurons carry signals from muscles to spinal cord, hence statements (ii) and (iii) are incorrect.

7. Which of the following statements are true about the brain?
(i) The main thinking part of brain is hind brain
(ii) Centres of hearing, smell, memory, sight etc are located in fore brain.
(iii) Involuntary actions like salivation, vomiting, blood pressure are controlled by the medulla in the hind brain
(iv) Cerebellum does not control posture and balance of the body
(a) (i) and (ii)
(b) (i), (ii) and (iii)
(c) (ii) and (iii)
(d) (iii) and (iv)
Ans. (c) (ii) and (iii)
Explanation: The main thinking part of the brain is forebrain and hence statement (i) is incorrect. Cerebellum controls posture and balance of the body and hence statement (iv) is incorrect.

8. Posture and balance of the body is controlled by
(a) cerebrum
(b) cerebellum
(c) medulla
(d) pons
Ans. (b) Cerebrum
Explanation: Refer to previous question’s explanation.
9. Spinal cord originates from
(a) cerebrum
(b) medulla
(c) pons
(d) cerebellum 
Ans. (b) medulla 
10. The movement of shoot towards light is
(a) geotropism
(b) hydrotropism
(c) chemotropism
(d) phototropism
Ans. (d) phototropism
Explanation: The term ‘phototropism’ is composed of two terms. ‘Photo’ means light and ‘tropism’ means growth.

11. The main function of abscisic acid in plants is to
(a) increase the length of cells
(b) promote cell division
(c) inhibit growth
(d) promote growth of stem
Ans. (c) Inhibit growth

12. Which of the following is not associated with growth of plant?
(a) Auxin
(b) Gibberellins
(c) Cytokinins
(d) Abscisic acid
Ans. (d) Abscisic acid
Explanation: It is an inhibitory hormone and hence is not associated with growth of plant.

13. Iodine is necessary for the synthesis of which hormone?
(a) Adrenaline
(b) Thyroxin
(c) Auxin
(d) Insulin
Ans. (b) Thyroxin
Explanation: This is the reason, deficiency of iodine results in hypothyroidism.

14. Choose the incorrect statement about insulin
(a) It is produced from pancreas
(b) It regulates growth and development of the body
(c) It regulates blood sugar level
(d) Insufficient secretion of insulin will cause diabetes
Ans. (b) It regulates growth and development of the body
Explanation: Insulin has no role to play in growth and development of the body.

15. Select the mis-matched pair
(a) Adrenaline: Pituitary gland
(b) Testosterone: Testes
(c) Estrogen: Ovary
(d) Thyroxin: Thyroid gland
Ans. (a) Adrenaline: Pituitary gland
Explanation: Adrenaline is secreted by adrenal gland.

16. The shape of guard cells changes due to change in the
(a) protein composition of cells
(b) temperature of cells
(c) amount of water in cells
(d) position of nucleus in the cells
Ans. (c) Amount of water in cells
Explanation: Excess amount of water results in guard cells becoming turgid, while lack of water results in flaccidity of guard cells.

17. The growth of tendril in pea plants is due to
(a) effect of light
(b) effect of gravity
(c) rapid cell divisions in tendrillar cells that are away from the support
(d) rapid cell divisions in tendrillar cells in contact with the support
Ans. (c) rapid cell divisions in tendrillar cells that are away from the support
Explanation: Due to this, there is more growth on portion away from support. This results in tendrils getting twined around the support.

18. The growth of pollen tubes towards ovules is due to
(a) hydrotropism
(b) chemotropism
(c) geotropism
(d) phototropism
Ans. (b) chemotropism
Explanation: Ovules release certain chemicals which stimulate the growth of pollen tubes towards ovules.

19. The movement of sunflower in accordance with the path of sun is due to
(a) phototropism
(b) geotropism
(c) chemotropism
(d) hydrotropism
Ans. (a) phototropism
Explanation: Refer to explanation for question 10.

20. The substance that triggers the fall of mature leaves and fruits from plants is due to
(a) auxin
(b) gibberellin
(c) abscisic acid
(d) cytokinin
Ans. (c) abscisic acid

21. Which of the following statements about transmission of nerve impulse is
incorrect?
(a) Nerve impulse travels from dendritic end towards axonal end
(b) At the dendritic end electrical impulses bring about the release of some chemicals
which generate an electrical impulse at the axonal end of another neuron
(c) The chemicals released from the axonal end of one neuron cross the synapse and
generate a similar electrical impulse in a dendrite of another neuron
(d) A neuron transmits electrical impulses not only to another neuron but also to muscle
and gland cells
Ans. (b) At the dendritic end electrical impulses bring about the releases of some chemicals
which generate an electrical impulse at the axonal end of another neuron.
Explanation: Chemicals are released from the axonal end and not from dendritic end.
22. Involuntary actions in the body are controlled by
(a) medulla in fore brain
(b) medulla in mid brain
(c) medulla in hind brain
(d) medulla in spinal cord
Ans. (c) Medulla in hind brain
Explanation: Medulla is a part of hind brain.
23. Which of the following is not an involuntary action?
(a) Vomiting
(b) Salivation
(c) Heart beat
(d) Chewing
Ans. (d) Chewing

24. When a person is suffering from severe cold, he or she cannot
(a) differentiate the taste of an apple from that of an ice cream
(b) differentiate the smell of a perfume from that of an agarbatti
(c) differentiate red light from green light
(d) differentiate a hot object from a cold object
Ans. (b) differentiate the smell of a perfume from that of an agarbatti
Explanation: When a person is suffering from severe cold, his olfactory receptors are blocked. Due to this, sense of smell is compromised.

25. What is the correct direction of flow of electrical impulses?

Ans. (c) Explanation: Dendrites of a neuron receive electrical impulse from axonal end of
another neuron. After that, electrical impulse travels through cell body, axon; to the
axonal end.
26. Which statement is not true about thyroxin?
(a) Iron is essential for the synthesis of thyroxin
(b) It regulates carbohydrates, protein and fat metabolism in the body
(c) Thyroid gland requires iodine to synthesise thyroxin
(d) Thyroxin is also called thyroid hormone
Ans. (a) Iron is essential for the synthesis of thyroxin
Explanation: It is iodine which is essential for the synthesis of thyroxin.

27. Dwarfism results due to
(a) Excess secretion of thyroxin
(b) Less secretion of growth hormone
(c) Less secretion of adrenaline
(d) Excess secretion of growth hormone
Ans. (b) Less secretion of growth hormone
Explanation: As the name suggests, growth hormone is responsible for proper growth in a person. Hence, lack of growth hormone would result in dwarfism.

28. Dramatic changes of body features associated with puberty are mainly because of secretion of
(a) oestrogen from testes and testosterone from ovary
(b) estrogen from adrenal gland and testosterone from pituitary gland
(c) testosterone from testes and estrogen from ovary
(d) testosterone from thyroid gland and estrogen from pituitary gland
Ans. (c) testosterone from testes and estrogen from ovary
Explanation: These are called sex hormones and are secreted from gonads. Testosterone is secreted in males and oestrogen is secreted in females.

29. A doctor advised a person to take an injection of insulin because
(a) his blood pressure was low
(b) his heart was beating slowly
(c) he was suffering from goiter
(d) his sugar level in blood was high
Ans. (d) his sugar level in blood was high
Explanation: if a person is suffering from diabetes then his blood sugar level may
become high. This disease is managed in some patients by administering insulin injection.
30. The hormone which increases the fertility in males is called
(a) oestrogen
(b) testosterone
(c) insulin
(d) growth hormone
Ans. (b) Testosterone

31. Which of the following endocrine glands is unpaired?
(a) Adrenal
(b) Testes
(c) Pituitary
(d) Ovary
Ans. (c) Pituitary
32. Junction between two neurons is called
(a) cell junction
(b) neuro muscular junction
(c) neural joint
(d) synapse
Ans. (d) synapse
33. In humans, the life processes are controlled and regulated by
(a) reproductive and endocrine systems
(b) respiratory and nervous systems
(c) endocrine and digestive systems
(d) nervous and endocrine systems
Ans. (d) nervous and endocrine systems
Explanation: Reproductive or respiratory systems have no role to play in control and coordination.

Ans. (a) Sensory neuron
 (b) Spinal cord
 (c) Motor neuron
 (d) Muscle

 

(a) elongation of cells
 Ans. Auxin
(b) growth of stem
 Ans. Giberellins
(c) promotion of cell division
 Ans. Cytokinin
(d) falling of senescent leaves.
 Ans. Abscisic acid 
 

 

Ans. (a) Pineal gland
 (b) Pituitary gland
 (d) Thyroid gland
 (d) Thymus

 

Ans. Figure ‘a’ appears more accurate. In this figure roots are showing positive geotropism, while shoot is showing negative geotropism.