Waec Biology 2012 Past Questions and Answers

Question 56:

• WAEC 2012

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

Question 57:

• WAEC 2012

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

Question 58:

• WAEC 2012

Two yellow-flowered hybrid plants each carrying a recessive factor for flowers with green colour were crossed.
Which of the following ratios shows the correct proportion of offspring that have green flowers?

A. 2 in 2
B. 1 in 3
C. 1 in 4
D. 1 in 5

Question 59:

• WAEC 2012

What name is given to a sudden change in a gene or chromosome?

A. Allele
B. Genotype
C. Mutation
D. Phenotype

Question 60:

• WAEC 2012

Bees are of great importance to the farmer because they

A. Provide him with honey
B. Pollinate flowers
C. Sting crop pests to death
D. Destroy flowers by sucking nectar from them