The fruit fly Drosophila melanogaster has four pairs of chromosomes, whereas the housefly Musca domestica has six pairs of chromosomes. How many different combinations of chromosomes are possible in the gametes of the fruit fly?

8

Explanation:

The fly has only 3 pairs of somatic chromosomes, that means that only can combine 3 chromosomes. To calculate the combinations the exponential 2n it is used. In this case is 2 to the third power that is equal = 2 x 2 x 2 = 8

This fly also has a fourth pair, but this one is the sexual one, so the main function of this gene is to give the sex to the offspring.