Answer
Caster Semenya is an athlete who possesses XY chromosomes, but has the external appearance of a female. This condition is called androgen insensitivity syndrome, and it means that Semenya's body does not respond to testosterone. As a result, she has developed female secondary sexual characteristics, such as breasts and a rounded pelvis. However, she also has some male characteristics, such as a deep voice and a muscular build.