What combination of sex chromosomes defines a typical male?

The combination of sex chromosomes that defines a typical male is XY. In humans, sex is determined by the presence of specific chromosomes. Males typically possess one X chromosome and one Y chromosome, resulting in the XY configuration. The Y chromosome carries genes that are essential for the development of male traits and the production of male gametes (sperm). This direct influence of the Y chromosome on male characteristics is fundamental to understanding sex differentiation in humans.

In contrast, the other combinations listed do not correspond to typical male chromosomal configurations. XX is characteristic of typical females, while YY is not a viable combination in humans, as it lacks an X chromosome necessary for essential functions. YX is also not a standard nomenclature and does not represent a recognized configuration in sexual differentiation. Thus, the XY configuration is the correct answer for defining a typical male.