An example of an organism in which females are the heterogametic sex and males are homogametic is:
The correct option is A
In birds, a different mechanism of sex determination is observed than in humans. In case of birds, the total number of chromosome is same in both males and females. But two different types of gametes in terms of the sex chromosomes, are produced by females, i.e., female heterogamety. In order to have a distinction with the mechanism of sex determination in humans and other organisms, the two different sex chromosomes of a female bird has been designated to be the Z and W chromosomes. In these organisms the females have one Z and one W chromosome, whereas males have a pair of Z-chromosomes besides the autosomes.