JAMB Biology Past Questions & Answers - Page 148

736.

The loss of soil through erosion can be reduced by

A.

watering

B.

crop rotation

C.

manuring

D.

irrigation

Correct answer is B

Advantages of Crop Rotation

  • Increases Soil Fertility.
  • Increases Crop Yield.
  • Increases Soil Nutrients.
  • Reduces Soil Erosion.
  • Limits the Concentration of Pests and Diseases.
  • Reduces the Stress of Weeds.
  • Improves the Soil Structure.
  • Reduces Pollution.

737.

During blood transfusion, agglutination may occur as a result of the reaction between

A.

contrasting antigens and antibodies

B.

two different antigens

C.

two different antibodies

D.

similar antigens and antibodies

Correct answer is D

For example, take the blood group A, it has antigen A and antibody B. When the anti-A antibody is used on this blood group, it causes a clumping. The anti-A antibody contains Antigen A. Hence, the clumping which is called AGGLUTINATION.

738.

How many alleles control blood grouping in humans?

A.

3

B.

4

C.

5

D.

2

Correct answer is A

No explanation has been provided for this answer.

739.

 Crossing individuals of the same species with different genetic characters is known as

A.

cross breeding

B.

polygenic inheritance

C.

non-disjunction

D.

inbreeding

Correct answer is A

No explanation has been provided for this answer.

740.

Which of the following theories was NOT considered by Darwin in his evolutionary theory?

A.

Variation

B.

Survival of the fittest

C.

Use and disuse

D.

Competition

Correct answer is C

No explanation has been provided for this answer.