Answers to Hands on Pg 36 -42

 (a)

(i) Pancreas secretes insulin

(ii) Glucose converted to glycogen in liver cells

 (iii) Some glucose converted to fat

 (iv) Rate of cellular respiration increases

(b) (i) Pancreas secretes glucagon

 (ii) Liver cells breaks down glycogen to glucose

 (iii) Some fats converted to glucose

 (iv) Rate of cellular respiration decreases

 (c) (i) Erector muscles relax to lower body hair

 (ii) Vasodilation

(iii) Sweat glands secrete sweat

 (iv) Decrease in metabolic rate

 (d) (i) Erector muscles contract to raise body hair to trap air

 (ii) Vasoconstriction

(iii) Skeletal muscles stimulated to cause shivering

 (iv) Increase in metabolic rate

Objective Pg 38-40

1. A 2. B 3. B 4. A  5. A 6. C 7. C 8. C 9. D 10. D   11. D 12. D  13. C  14. A 15. D

16. D 17. B

Subjective Questions Pg 41-42

1. (a) (i) X : Afferent neurone

Y : Efferent neurone

(ii) X : Transmits impulses from receptors to the central nervous system

Y : Transmits impulses from the central nervous system to effectors

C (ii) When an impulse reaches the synaptic knob, it causes the vesicle containing neurotransmitters to move to the membrane and release the neurotransmitters. These neurotransmitters diffuse across and attach to the membrane of the dendrite of the next neurone which then stimulate the transmission of impulse.

2. (a) (i) Auxin

(ii) To stimulate the growth of coleoptile and to enable the coleoptile to respond to a stimulus

 (b) In Experiment 1, the presence of auxin in the tip of the shoot stimulates the growth of the coleoptile. In Experiment 2, the growth is inhibited when the tip

of the shoot is cut.

C ii) Auxin stimulates growth even when the tip is covered but it cannot pass through aluminium to stimulate growth.

(d) The coleoptile grows straight upwards.

(e) (i) To stimulate the growth of adventitious roots

 (ii) To stimulate the development of fruits without fertilisation, i.e. parthenocarpy