WAEC Biology Past Questions & Answers - Page 147

732.

In a case of complete dominance, what is the phenotypic ratio of the cross Bb X Bb; where B =black and b = white?

A.

1 black : 1 grey : 2 whites

B.

1 black : 3 whites

C.

1 black : 2 blues : 1 white

D.

3 blacks : 1 white

Correct answer is D

No explanation has been provided for this answer.

733.

In the structure of DNA, which of the following statements is true?

A.

The double helix are held together by covalent bonds

B.

Nucleotide is made up of ribose, phosphate and an organic nitrogen compound

C.

Guanine is the opposite of cytosine

D.

Adenine is the opposite of cytosine

Correct answer is C

No explanation has been provided for this answer.

734.

Two plants with red flowers were back crossed, which of the following results indicate that the plants are heterozygous red flowers, where red flowers are dominant?

A.

75% red and 25% white

B.

50% red and 50% white

C.

100% white

D.

100% red

Correct answer is A

No explanation has been provided for this answer.

735.

Which of the following diseases is transmittable through genes?

A.

HIV /AIDS

B.

Sickle cell anaemia

C.

Diabetes

D.

Presbyopia

Correct answer is B

No explanation has been provided for this answer.