ECOLOGY - Jamb Biology Past Questions and Answers

Question 61:

• JAMB 1985

Water retention is highest in soils which are rich in

A. Sand, poor in humus and devoid of clay
B. Clay and sand, but poor in humus
C. Clay and humus, but poor in sand
D. Clay, poor in humus and devoid of sand
E. Sand and humus, but poor in clay

Question 62:

• JAMB 1985

The origin of mineral particles in the soil is

A. Humus
B. Water
C. Micro-organisms
D. Weathered rock
E. Organic matter

Question 63:

• JAMB 1985

Atmospheric nitrogen is directly replenished in nature through

A. The activities of denitrifying bacteria
B. The breakdown of ammonium salts in the soil
C. The activities of nitrifying bacteria
D. The activities of nitrogen-fixing bacteria in root nodules
E. Egestion, death and decay

Question 64:

• JAMB 1985

The initial volume of water poured into 60g bag of dry soil was 50ml and the amount that drained through was 35ml. The percentage water content of the fully soaked soil is therefore

A. 46.7
B. 25.0
C. 20.0
D. 30.0
E. 58.3

Question 65:

• JAMB 1986

In an ecosystem, animals which feed directly on plants are called

A. Secondary consumers
B. Primary consumers
C. Producers
D. Predators