Question

Describe the sex determination in human being. How does it differ from that of drosophila?

Answer 1

There are two pairs of sex chromosomes. One of the sex chromosomes is inherited to the offspring by the mother and the other is inherited from the father. The mother (females) have two X chromosomes and the father (males) will have X and Y chromosome. The chromosome which is inherited by the mother will be X. The father can inherit X or Y chromosome. If the father inherits Y chromosome, the offspring will be male.

There is XX/XY system which is used for the determination of sex in humans. There are X and Y sex chromosomes in Drosophila. The sex of the Drosophila is decided by the ratio of the X chromosome to the autosomes (X/A). The females have the ratio value equal to 1 and the males have a ratio of 0.5. When the ratio value is more than 1, the insect is metafemale. When the value is less than 0.5 the insect is metamale.