JAMB Biology Past Questions & Answers - Page 44

216.

Aged erythrocytes are destroyed in the

A.

pancreas

B.

liver

C.

lymph nodes

D.

kidney

Correct answer is B

Together with the spleen, the liver breaks down worn out red blood cells (erythrocytes).

217.

In the mammalian respiratory system. exchange of gases occurs in the

A.

lungs

B.

bronchi

C.

bronchioles

D.

alveoli

Correct answer is D

The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.

218.

In demonstrating the importance of mineral elements in plants, the culture bottle must be darkened to?

A.

prevent algal growth in culture solution

B.

allow root growth

C.

prevent breakdown of mineral elements

D.

prevents photosynthesis in the root

Correct answer is A

Always use a completely opaque water storage tank - Algae uses photosynthesis to reproduce. 

219.

When the original king and queen of termites die, they are replaced by 

A.

the king and queen of another colony

B.

some adult reproductives from the same colony

C.

some adult workers which are specially fed to breed

D.

developing nymphs nurtured as secondary reproductives

Correct answer is D

When the queen dies, production of the blocking pheromone stops, and secondary reproductives may be produced.

In the Reticulitermes species, the queen and king may be replaced by numerous secondary reproductives, and the colony may become very large with the added productivity of many queens.

220.

The initial volume of water poured into a bag of dry soil was 50ml and the amount that drained through was 35mI. The percentage of water content of the fully soaked soil is therefore

A.

46.7

B.

25.0

C.

20.0

D.

30.0

Correct answer is D

Percentage of water content (retained) = \(\frac{Water absorbed}{Weight of soil} * 100\) 

→ \(\frac{50 - 35}{50} * 100\)

= 30%