JAMB Biology Past Questions & Answers - Page 290

1,446.

Which is the most important pollutant of the marine environment in Nigeria?

A.

Insecticides

B.

Sewage

C.

Oil

D.

Inorganic fertilizers

Correct answer is C

No explanation has been provided for this answer.

1,447.

In a soil sample, the relative amouunts of the different soil particles can best be determined by the process of

A.

filtration

B.

centrifugation

C.

precipitation

D.

sedimentation

Correct answer is D

No explanation has been provided for this answer.

1,448.

After a heavy rainfall and the formation of a large pond, the most likely sequence of changes in the vegetation of the pond is

A.

Euglena → water lily → Spirogyra → grass

B.

water lily → Spirogyra →grass → Euglena

C.

Spirogyra → Euglena → grass → water lily

D.

Euglena → Spirogyra → water lily → grass

Correct answer is C

No explanation has been provided for this answer.

1,449.

The Southern Guinea Savanna differs from the Northern Guinea Savanna in that it has

A.

lower rainfall and shorter grasses

B.

less grasses and scattered trees

C.

more rainfall and taller grasses

D.

less arboreal and burrowing animals

Correct answer is C

No explanation has been provided for this answer.

1,450.

Adaptive features of plants to desert conditions include?

A.

thick barks, succulent stems, and sunken stomata

B.

thin barks, succulent stems, and sunken stomata

C.

thin barks, air floats on stems, and sunken stomata

D.

air spaces in tissues, adventitious roots, and thick barks

Correct answer is A

The leaves and stems of many desert plants have a thick, waxy covering.

This waxy substance does not cover the stomata, but it covers most of the leaves, keeping the plants cooler and reducing evaporative loss.

Small leaves on desert plants also help reduce moisture loss during transpiration.

Eg cactus plants: · thick, waxy skin to reduce loss of water and to reflect heat · large, fleshy stems to store water · thorns and thin, spiky or glossy leaves.