JAMB Biology Past Questions & Answers - Page 401

2,001.

Root hair have their origin from

A.

Endodermis

B.

Pericycle

C.

Cortex

D.

Epidermis

E.

Xylem

Correct answer is D

Asymmetric cell division in an epidermal cell gives rise to a large cell (atrichoblast) that develops into a hairless epidermal cell and a shorter 'specialized' cell that forms a root hair (trichoblast).

2,002.

Insect show consideration powers of water conservation. This is due to the fact that

A.

The chitinous cuticle is impregnated with tanned protein

B.

Nitrogenous waste is eliminated as urea

C.

Chitin is impermeable to water

D.

The malpighian tubules are impermeable to water

E.

The curticle is covered with wax

Correct answer is C

No explanation has been provided for this answer.

2,003.

Which of these is not true? grass in the above food chain

A.

trap all the sunlight

B.

trap a small percent of the sun energy

C.

are primary producers

D.

are eaten by primary consumers

E.

contains chlorophyll

Correct answer is A

No explanation has been provided for this answer.

2,004.

Grasses grasshopper lizard snakes hawks. In the food chain, the organism which are the least in number are

A.

grasses

B.

grasshopper

C.

lizards

D.

snakes

E.

 hawks

Correct answer is E

No explanation has been provided for this answer.

2,005.

The major function of contractile vacuole in amoeba is? 

A.

to secrete enzyme to digest food particles

B.

to store excess food materials

C.

to excrete nitrogenous waste

D.

to absorb water from the surrounding

E.

to collect and expel water in the cytoplasm

Correct answer is E

- The contractile vacuole (CV) complex is an osmoregulatory organelle of free-living amoebae and protozoa, which controls the intracellular water balance by accumulating and expelling excess water out of the cell, allowing cells to survive under hypotonic stress as in pond water.

- This implies that the contractile vacuole, as its name suggests, expels water out of the cell by contracting.