Jjj Flashcards
The fruit fly Drosophilia melanogaster has four pairs of chromosomes, whereas the house fly Musca domestica has six pairs of chromosomes. All things being equal, in which species would you expect to see more genetic variation among the progeny of a cross? Explain your answer.
The progeney of an organism whose cell contains more homologous pairs of chromosomes should be expected to exhibit more variation. The number of different combinations of chromosomes that are possible in the gametes is 2^n, where n is equal to the number of homologous pairs of chromosomes. For the fruit fly with four pairs of chromosomes, the number of possible combinations is 2^4 = 16. For Musca domestica with six pairs of chromosomes the number of possible combinations is 2^6=64
