(a) State eight human activities that may pollute water bodies

(b) Explain the measures that may be used to prevent pollution of water bodies.

(c) Mention four methods of purifying water. 
 

(a)(i) Define tropic and nastic movements.
(ii) List four differences between tropic and nastic movements.

(b) Describe an experiment to show that auxins are produced in the apical cells of a shoot.

(c)(i) Name two plant hormones, other than auxins.
(ii) Give two examples of tropism. 

(a) what is an ecosystem?

(b) Name twi abiotic factors each which affect plants and animals in a terrestrial habitat

(c) Describe the effect of three abiotic factors pn a named plants and an animal in the habitat mentioned in (b) above

(a) What is a sense organ?

(b)(i) State two main functions of the ear
(ii) Explain the mechanism involved in one of the functions stated in (b) (i) above.

(c) With the aid of a large labelled diagram, illustrate the eye defect of short-sight and its correction.
 

(a) State five different methods used in vegetative propagation in plants giving an example in each case. 

State five (i) advantages and (ii) disadvantages of vegetative propagation.