(a) What are hormones?

(b) In a tabular form, state four differences between nervous coordination and hormonal coordination in humans.

(c) State three effects each of: (i) Over-secretion (ii) Under-secretion of thyroxin on mammals.

(d) Make a diagram 10 - 12cm long of the reflex arc and label fully.

(a) Explain the following modes of nutrition which occur in plants:
(i)Autotrophic
(ii) Chemosynthetic
(iii) Carnivorous

(b) Give one example each of a plant which undergoes the modes of nutrition listed in (a) above.

(c) (i) Describe three ways by which nitrogen is added to the soil for plant use.
(ii) State two ways by which nitrogen is lost from the soil. 
 

(a) In a tabular form distinguish between tropic movement and nastic movement

(b) Explain how light brings about tropic movement in the stem and root of a flowering plant.

(c) What would be observed when a growing seedling is placed horizontally?

(d) State five functions of the pituitary gland

(e) State two difference between growth in plants and growth in animals.

(a) What is a balanced diet?

(b) Name the classes of food stating the importance of any two to the human diet.

(c) In a tabular form, state the source, substrate and end products of the following enzymes: (i) ptyalin: (ii) pepsin; (iii) lipase.
 

(a) Define the following terms:
(i) gene
(ii) gene mutation.

(b) Name two structures each of plants and animals where the following processes take place:
(i) mitosis
(ii) meiosis.

(c) State four advantages a farmer may hope to derive in cross breeding two different breeds of cows.

(d) State three applications of the knowledge of genetics in medicine.