waecE-LEARNING
Geography Paper 1B ,May/June 2013  
Questions:   1 2 3 4 5 6 7 8   Main
General Comments
Weakness/Remedies
Strength

Question 7

(a) Define ecosystem.

(b) Describe any four ways in which man has interfered with the ecosystem.

(c) With specific examples, outline three effects of man’s interference with the ecosystem.

OBSERVATIONS

 

This was a popular question among the candidates and most of those who answered the question performed well except for a few candidates who misunderstood the effects of man’s interference with the ecosystem to mean ways in which man has interfered with the ecosystem. The ways in which man has interfered with the ecosystem included:

- Pollution: Man has injected toxic waste into the ecosystem in various ways such as oil spillage, use of DDT, excessive use of fertilizers, release of fumes to atmosphere via motor vehicles, factory operations, combustion of waste etc;

- Construction: construction projects e.g. road construction alters the natural ecosystem;

- Overgrazing: overgrazing grassland with farm animals leads to the extinction of some valuable species;

- Deforestation: felling down of trees for lumbering and fuel wood, cultivation and settlement has led to the loss of valuable forest plants and animals which are of great value to man;

- Mining: exploitation of mineral resources alters the natural landscape and permanently deform the land if reclamation measures are not undertaken;

- Urbanisation: the expansion of human settlements leads to the creation of a derived environment other than the natural environment. Significant alterations in the environment lead to the extinction of flora and fauna;

- Farming practice: all agricultural practices alter the natural surrounding leading to loss of some plant and animal species;

- Industrialization: Industrialization has led to the creation of new products some of which are harmful to the environment e.g. the release of chloroflouro carbon to the atmosphere leads to the destruction of ozone layer.

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