JAMB Biology Past Questions & Answers - Page 373

1,861.

In the enzyme (amlyase) reactions of starch → sugar
starch is referred to as the

A.

substrate

B.

product

C.

enzyme

D.

enzyme-substrate complex

E.

reaction mixture

Correct answer is A

No explanation has been provided for this answer.

1,862.

ONE of the major causes of haemophilia is lack of

A.

firbrinogen

B.

amylase

C.

white blood corpuscles

D.

red blood corpuscles

E.

plasma

Correct answer is A

No explanation has been provided for this answer.

1,863.

In man, identical twins occur when

A.

 An ovum is fertilized by a sperm and then divide into two, each forming a separate embryo

B.

an ovum fertilized by two sperms and then divides into two, each forming an embryo

C.

two ova are fertilized at the same tine each forming an embryo

D.

two ova are fertilized by a single sperm each forming an embryo after fertilization

E.

one ovum first divides into two and each half is fertilized by a sperm before developing into an embryo

Correct answer is A

No explanation has been provided for this answer.

1,864.

A physiological adaptation of plants to the problem of excessive water loss is

A.

reduction in the number of stomata

B.

reversal of the normal stomatal rythm

C.

possession of shallow roots

D.

possession of waxy cuticle

Correct answer is B

No explanation has been provided for this answer.

1,865.

The parts of the mammalian eye that strongly bend light rays are the

A.

cornea and the lens

B.

cornea and aqueous humour

C.

cornea and vitreous humour

D.

lens and aqueous humour

E.

lens and vitreous humour

Correct answer is A

- The cornea acts as the eye's outermost lens. It functions like a window that controls and focuses the entry of light into the eye. The cornea contributes between 65- 75 percent of the eye's total focusing power. When light strikes the cornea, it bends--or refracts--the incoming light onto the lens.