(i) Effect of gravity on plant growth: The (main) root grows down in response to gravity/positively geotropic; the (main) stem/shoot/grows upwards away from gravity/negatively geotropic.
(ii) Experiment to demonstrate the effect of gravity on the roots of a plant: -

Select three germinating bean seedlings/seeds on a moist/damp sawdust/wet blotting paper
Pin/keep one seedling in a horizontal position
Place another seedling in a vertical position with the radicle pointing upwards
Place the third upwards vertical with the radicle pointing downwards, to serve as control
After few/2-3 days, it will be observed that the radicle of the seedling placed horizontally bends/ grows downwards
the radicle of seedling placed vertically bends/grows downwards
Indicating positive geotropism/ positive response to gravity.
The seedling placed vertically with radicle point downwards did not bend. (N.B. observation must correspond with the experimental procedure to score).

ALTERNATIVE to 1 (a)

(ii) Take a clinostat and two bean seedlings
Pin one seedling horizontally on damp/moist/wet/cotton wool/blotting paper attached to the cork of the clinostat
Pin the other seedling onto some damp/moist/wet cotton wool/blotting paper attached to the cotton tile
Start the motor of the clinostat; Observe the seedlings after 8 —10 hrs.
It will be observed that the radical of the seedling placed horizontally bends/grows down wards
Indicating/showing positive geotropism.

(b) Detection of bitter taste in humans

Taste buds are unevenly distributed on the surface of the tongue
Taste buds for detecting bitterness are at the back/end of the tongue
For a substance to be tasted it must be dissolved in a solution/saliva
When bitter substance is dissolved in saliva, sensory cells at end/back of the tongue are stimulated
Which pass impulses to the brain; Which interprets the taste as bitter.

(c) Hormones of endocrine glands and their functions

S/N	Endocrine glands	Hormone produced	Function
1	Thyroid	Thyroxin	influences growth/development; Regulates/controls rates of metabolism
23	PancreasOvary/ovaries	InsulinOestrogen	Control blood sugar level/causes liver to convert to convert glucose to glycogenDevelopment of secondary sexual characters of females