Waec Biology 1991 Past Questions and Answers

Question 56:

• WAEC 1991

The wing of a bat and that of a bird, the flippers of a whale and the fins of s fish are example of

A. Adaptive radiation
B. Vestigial structures
C. Continuous variation
D. Convergent evolution
E. Divergent evolution

Question 57:

• WAEC 1991

In an individual who is heterozygous for a particular character, the hereditary factor that is always expressed is described as

A. Allele
B. Sickle-cell gene
C. Dominant gene
D. Chromosome
E. Sex-linked character

Question 58:

• WAEC 1991

Which of the following statements best explains the meaning of homologous chromosomes?

A. Product of division of chromosomes
B. Two identical chromosomes from each parent
C. Chromosome arranged on spindle fibre during cell division
D. Chromosome arranged on the equatorial plate of the cell
E. Daughter chromatide in the first melotic division

Question 59:

• WAEC 1991

(a)(i) Explain briefly the cell theory.
(ii) Name two scientists who contributed to the development of the cell theory.
(b) Make a large labelled diagram of a typical plant cell.
(c) List three ways in which a typical plant cell differs from a typical animal cell.
(d) State one difference each between Hydra and the mammals with respect to:
(i) level of organisation; (ii) symmetry; (iii) number of body layers.

Question 60:

• WAEC 1991

(a) Make a labelled diagram to show the internal structure of the mammalian ear.
(b) Describe the mechanism of hearing in mammals.
(c) State two ways of caring for the ear.