JAMB Biology Past Questions & Answers - Page 55

271.

Both recesssive and dominant characters are found

A.

on different chromosomes in the cell

B.

at the same locus of a homologous chromosome

C.

at a different loci of a homologous chromosome

D.

on the same chromatid in a chromosome

Correct answer is B

No explanation has been provided for this answer.

272.

In which of the following groups of vertebrates is parental care mostly exhibited?

A.

Aves

B.

Reptilia

C.

Amphibia

D.

Mammalia

Correct answer is D

No explanation has been provided for this answer.

273.

For growth to occur in organisms, the rate of

A.

anabolism must exceed that of catabolism

B.

catabolism must exceed that of anabolism

C.

food storage must be low

D.

food storage must be high

Correct answer is A

Anabolism centers around growth and building the organization of molecules. In this process, small, simple molecules are built up into larger, more complex ones while Catabolism is what happens when you digest food and the molecules break down in the body for use as energy.

274.

Vaccination is carried out in order to

A.

check the production of poison

B.

increase the activities of white blood cells

C.

increase the number of red blood cells

D.

stimulate the production of antibodies

Correct answer is D

No explanation has been provided for this answer.

275.

When sickle cell carrier marries a normal woman, the probability of them having a normal offspring is

A.

0.75

B.

0.25

C.

0.5

D.

0.1

Correct answer is C

A sickle cell carrier (AS) and a normal woman (AA), when crossed will yield: 2 normal offsprings (AA) and 2 sickle cell carrier (AS). Hence, the probability of a normal child = \(\frac{2}{4}\) = \(0.5\)