Write short note on sex determination in humans.

Sex determination in humans is XX-XY type. Apart from humans, XX-XY system of sex determination is found in most mammals and some insects. In humans, there are total 46 chromosomes. Out of these 46 chromosomes, 44 are autonomies and 2 are sex chromosomes. The sex chromosomes are X and Y. Both X and Y chromosomes are different in size and shapes. They also carry different sets of genes. Females have two same chromosomes (XX) whereas males have two different sex chromosomes (XY). Hence, females have 44 + XX chromosomes and males have 44 + XY chromosomes. During gamete formation, female produces only one type of gamete 22 + X. Whereas, male produces two types of gametes, namely 22 + X and 22 + Y.