How does the SRY gene affect sexual determination in mammals?

The SRY gene, which stands for Sex-determining Region Y, plays a crucial role in sexual determination in mammals, particularly in the development of male traits. It is located on the Y chromosome and is responsible for initiating the pathway that leads to the development of male gonads, specifically the testes. When the SRY gene is activated, it triggers a cascade of genetic events that promote the formation of testes, which then produce male hormones like testosterone. These hormones are essential for the development of male physical characteristics, such as the formation of the penis and scrotum, as well as the development of secondary sexual characteristics during puberty.

In contrast, the other options do not accurately reflect the role of the SRY gene. The gene does not influence the formation of ovarian tissue; instead, its absence or inactivation leads to ovarian development. It also has a significant effect on sexual differentiation, contradicting the suggestion that it has no effect. Furthermore, while the SRY gene is vital for male development, it does not play a direct role in determining female traits, which emerge when the SRY gene is not expressed. Thus, the correct understanding of the SRY gene's function is why its influence on dictating the presence of male physical characteristics