WAEC Biology Past Questions & Answers - Page 111

551.

Which of the following statements defines plasmolysis?

A.

Shrinking of a plant cell in a solution

B.

Shrinking away of cytoplasm from an animal cell membrane

C.

Shrinking away of the cytoplasm from the plant cell wall

D.

shrinking of the vacuole and leaving the cytoplasm attached to the cell wall

Correct answer is C

No explanation has been provided for this answer.

552.

Which of the following substance pass through the root cell membrane by osmosis?

A.

Cell sap

B.

Carbon dioxide

C.

oxygen

D.

water

Correct answer is D

No explanation has been provided for this answer.

553.

In active transport, molecules move against a concentration gradient, therefore

A.

molecules move from a region of low concentration to a region of high concentration

B.

molecules move from a region of high concentration to a region of low concentration

C.

the concentration gradient has little effect on the movement of molecules

D.

molecules force their way through special channels

Correct answer is A

No explanation has been provided for this answer.

554.

Which of the following Best explains why It is difficult to see clearly in dim light?

A.

Initially the eyes cannot operate when the light is dim

B.

The choroid reflect all the light that enters the eye

C.

Too little light reaches the retina and so the cones may not be stimulated at all

D.

Dim light causes the pupil to close up so that not much light enters the eye

Correct answer is C

No explanation has been provided for this answer.

555.

Which of the following pairs of organisms exist as colonies?

A.

Obelia and Euglena

B.

Pandorina and Volvox

C.

Chlamydomonas and Amoeba

D.

Hydra and Spirogyra

Correct answer is B

No explanation has been provided for this answer.