Q. Consider the following statements:
1.Males have two X chromosomes, while females have one X and one Y chromosome.
2.The X chromosome is significant for determining gender as well as diseases.
3.X Chromosome Inactivation (XCI) is a process that occurs in female mammals to achieve dosage compensation for X-linked genes.
How many of the statements given above are correct?
Explanation –
Statement 1 is incorrect. Males have one X and one Y chromosome, while females have two X chromosomes. This chromosomal difference between males and females is the basis of sex determination in mammals.
Statements 2 and 3 are correct. The X chromosome is significant not only for determining sex but also for its role in various biological functions and disease susceptibilities. The human X chromosome encodes around 800 genes, which are crucial for numerous cellular processes. Loss of function in these genes can lead to a variety of genetic diseases. X Chromosome Inactivation (XCI) is a process occurring in female mammals to balance the gene expression levels of X-linked genes between the sexes. One of the two X chromosomes in female cells is transcriptionally silenced to achieve this dosage compensation.
Source: The Hindu
