Question

Briefly discuss chromosome theory of sex determination ?​

Answer 1

Complete answer:

1. Chromosome plays an important role in determining the sex of an individual. Chromosomes are a thread-like structure holding genetic information. It is present in the cell nuclei. A normal cell contains 23 pairs (46n) of chromosomes. Out of these, one pair (2n) is sex chromosomes. Sex chromosomes are denoted as X and Y. A male cell carries XY sex chromosomes while a female cell carries XX sex chromosomes. A gamete contains only 23 chromosomes (23n). Sperm carries either an X or Y chromosome, i.e. there will be two sets of sperms. One set of sperm made up of only X chromosomes, while another set made up of only Y chromosomes. An ovum always carries an X chromosome. The sex of the kid depends on the type of sperm that fuses with the ovum. During sexual intercourse, the father ejects both types of sperms, i.e. X chromosome and Y chromosome sperms. 1. If the sperm with an X chromosome fertilizes the ovum of the X chromosome, the zygote would have XX chromosomes, and the child will be a girl. 2. If the sperm with the Y chromosome fertilizes the ovum of the X chromosome, then the zygote would have XY chromosomes, and the child will be a boy.