question_answer

The female fruitfly and the male fowl are homogametic while the male fruitfly and female fowl are heterogametic, why are they called so?

Answer:

It is due to the different types of sex - determination pattern in both cases. In the first case, the female fruitfly has XX while the male fruitfly has XY The former is homogametic as produces similar type of gametes whereas the latter is heterogametic as produces different types of gemetes. Similarly, in the second case, the male fowl has similar chromosomes, i.e. ZZ (homogametic) whereas female fowl has dissimilar chromosomes, i.e. ZW (heterogametic).