WAEC Biology Past Questions & Answers - Page 195

971.

Vaccination results in

A.

aiding red blood cells to carry more oxygen

B.

production of antibodies that destroy germ toxins

C.

arresting excessive bleeding

D.

production of white blood cells which engulf and digest bacteria

Correct answer is B

No explanation has been provided for this answer.

972.

Which of the following methods does not make water fit for drinking?

A.

Addition of chlorine

B.

Boiling

C.

Distillation

D.

Addition of alum

Correct answer is C

Chlorine is one of the most commonly used for water disinfection. Adding chlorine helps kill certain bacteria and other microbes in tap water.

973.

Assuming that a period of stable population size is followed by a period when natality increases by ten (10) percent and immigration increases by twenty (20) percent of population size. The population size will

A.

be at equilibrium

B.

increase by forty (40) percent

C.

begin to increase

D.

begin to decrease

Correct answer is C

No explanation has been provided for this answer.

974.

A wet garden soil sample of a known weight was heated to constant weight. The weight was lost due to a loss of

A.

water

B.

organic matter

C.

water and organic matter

D.

water and inorganic matter

Correct answer is C

No explanation has been provided for this answer.

975.

The falling off of leaves of deciduous trees is helpful to the plant because it

A.

reduces the rate of transpiration

B.

enables the plant to conveniently eliminate its excretory products

C.

enables the plant to bear more fruits

D.

ensurereduces the rate of transpirations that the limited mineral salts get to only growing regions

Correct answer is A

No explanation has been provided for this answer.