JAMB Biology Past Questions & Answers - Page 407

2,031.

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.

2,032.

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.

2,033.

The one-seeded fuit in which the pericarp and the seed coat have become fused together is known as

A.

achene

B.

samara

C.

caryopsis

D.

legume

E.

drupe

Correct answer is C

No explanation has been provided for this answer.

2,034.

Identical twins are produced under one of the following conditions

A.

Two oval fertilized at the same time by two sperm

B.

one ovum ferilized divides to give two embryos

C.

one ovum fertilized, twins formed shortly before birth

D.

Two ova fertilized by one sperm

E.

one ovum fertilized by two sperm

Correct answer is B

No explanation has been provided for this answer.

2,035.

The maize grain is regarded as a fruit and not a seed because

A.

It is covered by a sheath of leaves

B.

The testa and fruit wall fuse after fertilization

C.

It has both endosperm and cotyledon

D.

It has coleorhiza and coleoptile

E.

The pericarp and seed coat are separated

Correct answer is B

No explanation has been provided for this answer.