NEET BIOLOGY

Detailed explanation-1: -Because only males have the Y chromosome, the genes on this chromosome tend to be involved in male sex determination and development. Sex is determined by the SRY gene, which is responsible for the development of a fetus into a male.

Detailed explanation-2: -The Y chromosome contains a “male-determining gene, ” the SRY gene, that causes testes to form in the embryo and results in development of external and internal male genitalia. If there is a mutation in the SRY gene, the embryo will develop female genitalia despite having XY chromosomes.

Detailed explanation-3: -In humans, sex is determined by sex chromosomes (XX females, XY males). The X and Y chromosomes harbor dramatically different numbers and sets of genes (about 1, 000 genes on the X and only a few dozen genes on the Y), yet they originated from ordinary autosomes during the early evolution of mammals (Figure 1).

Detailed explanation-4: -The same is true of all other placental mammals-males produce X and Y gametes, and females produce only X gametes (Figure 4). In this system, referred to as the XX-XY system, maleness is determined by sperm cells that carry the Y chromosome.