(a)(i) What is conservation?
(ii) State six factors responsible for the decline of the abundance and variety of wildlife.

(b) Outline six ways in which the government can improve the situation in (a)(ii) above.

(c)(i) What is Eutrophication?
(ii) State two causes of eutrophication.
 

(a) Describe the carbon cycle.

(b) State the functions of:
(i) nitrogen fixing bacteria
(ii) nitrifying bacteria
(iii) denitrifying bacteria; in nature. 
 

(a)(i) What is excretion?
(ii) List the excretory organs in humans and name one waste product excreted by each organ

(B) Name the excretory organs in:
(i) insects
(ii) earthworms. 
 

(a) Explain briefly four factors that affect the diffusion of substances.

(b) Explain the following terms:
(i) active transport
(ii) transpiration.

(c) State four ways by which plants can reduce high rate of transpiration.

(d) State the features of red blood cells and how these features adapt the cell to perform its functions. 

(a) Describe briefly the role of the stomach in digestion.

(b) (i) Name three parts of plants in which food can be stored.
(ii) Give one example in each case.

(c) Explain briefly how the level of sugar in the mammalian blood can be regulated.