Question

Explain the sex determination in humans.

Answer 1

The sex determination in humans is based on the XX and XY chromosomes. In males, the XY chromosomes are present. During the gamete formation, 50% of the sperms receive the X-chromosomes and 50% of the sperms receive the Y-chromosomes. Hence, males are heterogametic. In females, there are XX chromosomes, so all the gametes have X chromosomes. Now, during the time of fertilization, when the X-chromosome containing sperm fuses with ovum, XX condition occurs and a female will be born. When the Y-chromosome containing sperm fuses with ovum, XY condition occurs and a male will be born. Hence, in an event of fertilization, there are 50-50 chances for a male and a female foetus.