(a) Write short notes on each of the following: (i) ecosystem; (ii) population; (iii) ecological succession in plants.

(b) List five ways by which nitrogen can be made available to the soil for plant growth. 
 

(a) Explain the term, conservation of natural resources.

(b)(i) List seven methods of soil conservation.

(ii) Name four other natural resources that may be conserved.

(c) State three factors which negatively affect conservation of forest in West Africa.

(d) Describe what happens during the denitrification stage of the nitrogen cycle. 
 

(a) What is a hormone?

(b) Outline the role played by adrenaline in an emergency situation.

(c) In a tabular form, list five differences between hormonal co-ordination and nervous co-ordination.

(d) Name three animal hormones and two plant hormones. 
 

(a)(i) Briefly explain the term respiration.

(ii) Name the two types of respiration and write a balanced equation to summarize each of them.

(b) Outline the mechanisms involved in: (i) inhalation; (ii) exhalation in human beings 
 

(a) Write a short note on the importance of the presence of an effective transport system in mammals.

(b) state eight functions of blood in mammals.

(c) list four materials transported in the bodies of flowering plants.