Waec Biology 2004 Past Questions and Answers

Question 66:

• WAEC 2004

(a) Explain briefly the following terms:
(i) phenotype
(ii) hybrid
(iii) dominant character.
(b) Two varieties of maize, one with yellow (Y) grains and the other with purple (y) grains were crossed and all their offspring had yellow grains. When the offspring were crossed with the parent variety with purple grains, half of the resulting offspring had yellow grains, while the other half had purple grains. Using labelled diagrams only;
(i) deduce the genotype of the grains of the first filial generation,
(ii) show the results of the cross between the first filial generation and the parent purple variety.
(c) Mention two ways in which the application of genetics is beneficial to agriculture.