Question

Write a short note on sex chromosomes.

Answer 1

Sex chromosomes are a pair of chromosomes that determine the sex of an individual. In humans, there are 23 pairs of chromosomes, out of which 22 pairs are autosomes, and one pair consists of sex chromosomes. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). The presence of the Y chromosome determines male characteristics. Females produce gametes with only X chromosomes, whereas males produce gametes with either X or Y chromosomes. The combination of these during fertilization determines the sex of the offspring: XX for female and XY for male.