What type of chromosomes determine a male biological sex?

The determination of biological sex in many organisms, including humans, is mainly influenced by the presence of specific sex chromosomes. In humans, males possess one X chromosome and one Y chromosome, which is the defining characteristic for biological male sex. The Y chromosome contains genes that are crucial for the development of male characteristics, including the SRY gene, which triggers the formation of testes and the production of male hormones.

In contrast, an individual with two X chromosomes typically develops as female because the genetic instructions provided by the two X chromosomes do not include the male-determining SRY gene found on the Y chromosome. The other options, such as combinations involving Z chromosomes or two Y chromosomes, do not align with known human sex determination mechanisms. Therefore, the presence of one X and one Y chromosome is the defining factor for male biological sex, making this the correct choice.