Biological Systems MCAT Practice Exam 2026 – Complete Study Resource

The Y chromosome plays a crucial role in male sex determination due to the presence of specific genes that drive the development of male sexual characteristics. One of the primary genes found on the Y chromosome is the SRY (Sex-determining Region Y) gene. This gene triggers the formation of testes, which subsequently produce male hormones like testosterone that promote the development of male physical traits and reproductive structures.

While the other options may involve various biological processes or functions, they are not directly related to the key role of the Y chromosome in determining male sex. For example, the regulation of estrogen development primarily involves other genes and chromosomes, particularly on the X chromosome. Similarly, apoptosis and ovulation are processes that are influenced by different genetic and hormonal mechanisms not primarily associated with the Y chromosome's role in sex determination. Therefore, the function of containing genes for male sex determination clearly highlights the significance of the Y chromosome in male biology.