Answer the following question given this paragraph: 

A sex chromosome is a chromosome that determines the sex of an organism. Humans have two sex chromosomes, X and Y . Females have two X chromosomes ( XX ), and males have one X and one Y chromosome ( XY ). An autosome is any chromosome other than a sex chromosome. If a trait is autosomal it will affect males and females equally.


Q: What chromosome determines the sex of an organism?


A:
sex chromosome