What type of sex chromosomes do mammals have?

Mammals typically possess the sex chromosome system designated as XX/XY. In this system, females have two of the same type of sex chromosome (XX), while males have one of each type (XY). This chromosomal configuration is fundamental in determining the sex of the individual, as the presence of the Y chromosome in males often leads to male-specific traits and development, largely influenced by the SRY gene located on the Y chromosome.

This system of chromosomal determination is a classic example of how genetics influence biological sex, providing a clear understanding of inheritance patterns and how sex-linked traits can be passed down through generations. Understanding the XX/XY system is crucial for the study of genetics and its implications in mammalian biology, reproductive strategies, and evolutionary context.