Waec Biology 1991 Past Questions and Answers

Question 41:

• WAEC 1991

The role of dead organic matter in the soil is to

A. Make the soil black
B. Increase the mineral salt content
C. Provide food for all living organisms
D. Increase the acidity of soil
E. Make the soil more porous

Question 42:

• WAEC 1991

Species do not change in order to survive. The environment determines which organism survives to reproduce. These statements

A. Explains theory of acquired characters
B. Supports Jean Lamarck's theory of use and disuse
C. Support the idea of survival of the fittest
D. Are refuted by fossil record
E. Imply that organisms modify their environment in order to survive

Question 43:

• WAEC 1991

Which of the following may not contribute to environmental pollution?

A. Solar energy radiation
B. Industrial waste
C. Waste disposal
D. Smoke
E. Nuclear power plant

Question 44:

• WAEC 1991

Succession is best described as

A. A process whereby organisms systematically colonize a barren habitat until stable community is formed
B. A process whereby plant occupy a barren habitat until a suitable habitat is formed
C. A process whereby animals occupy a barren habitat until a suitable habitat is formed
D. The subsequent taking over of the land through emigration or dispersal of seeds
E. The replacement of weaker plants and animals by stronger ones

Question 45:

• WAEC 1991

Predators are beneficial in pest control because they

A. Are natural enemies of small mammals
B. Devour farm animals
C. Feed on pests of crops
D. Prey on game animal
E. Compete for food with the pests