JAMB Biology Past Questions & Answers - Page 236

1,176.

An insect with a mandibulate mouth part will obtain its food by

A.

biting and chewing

B.

chewing and sucking

C.

chewing

D.

sucking

Correct answer is A

No explanation has been provided for this answer.

1,177.

The type of reproduction that leads to variation in animal and plant populations is

A.

budding

B.

sexual

C.

vegetative

D.

asexual

Correct answer is B

No explanation has been provided for this answer.

1,178.

A feature associated with the Y-chromosome in humans is

A.

long eyelashes

B.

 prominent fingernails

C.

facial hairs

D.

enlarged breast

Correct answer is C

No explanation has been provided for this answer.

1,179.

An organism that has been extensively used to test the chromosomes theory of heredity is

A.

Drosophila melanogaster

B.

Muscar domestica

C.

Zea mays

D.

Homo sapiens

Correct answer is A

No explanation has been provided for this answer.

1,180.

A man and his wife are both heterozyous for the sickle-cell trait. The likely percentage of their offspring being either carriers or sicklers is

A.

75%

B.

50%

C.

25%

D.

100%

Correct answer is A

A heterozygote for sickle-cell anaemia = AS

Crossing two AS persons, we have one AA, two AS, and one SS.

∴ The probability that the children are either carriers or sicklers = ¾

= 75%