State the principles involved in the following methods of food preservation:
(a) (i) Salting (ii) Refrigeration (iii) Drying (iv) Smoking (v) Chemicals.

(b) State four problems that may be caused by human overpopulation.

(c) Explain three ways by which the Government may increase food production. 
 

(a) (i) Define the term hydrosphere.
(ii) Give three examples of hydrosphere.

(b) (i) State the two laws of thermodynamics levels.

(c) (i) Name two local biotic communities in Nigeria and associate each type with a particular State in Nigeria.
(ii) List three factors that affect organisms in the marine habitat.
(iii) State three adaptive features of sea weeds. 
 

(a) (i) Define the law of independent assortment.
(ii) State the findings from Mendel's experiment involving white-flowered and red-flowered pea plants.
(iii) Illustrate these findings by means of simple diagrams.

(b) Explain why blood groups A and B in man can exist both in heterozygous and homozygous conditions while blood group 0 can only exist in homozygous state. . 
 

(a) (i) What is Pollution?
(ii) Name two pollutants each of air and water.

(b) (i) State four effects of water pollution.
(ii)Mention four ways of preventing water pollution in an environment.

(c) (i) Name three sources of noise pollution.
(ii) State three effects of noise pollution on man.
 

(a) (i) Define the term metamorphosis.
(ii) Name the two types of metamorphosis that organisms undergo and mention two organisms that undergo each type.

(b) (i) State four economic importance of insects and name an example of each of the insects involved.
(ii) List four peculiar features of social insects.