In humans, clear gender differentiation occurs not at fertilization, but after the second month of gestation. Which of the following statements describes the first event of this differentiation?
A) formation of testosterone in male embryos
B) formation of estrogens in female embryos
C) activation of SRY in male embryos and masculinization of the gonads
D) activation of SRY in females and feminization of the gonads

Question

Quizplus · Accepted Answer

The first event of gender differentiation in humans is the activation of the SRY gene on the Y chromosome in male embryos, which leads to the development of masculine gonads and the production of testosterone. This process occurs around the 7th week of gestation. Option A and B are not the first event of gender differentiation. Option D is incorrect as activation of SRY gene is only present in male embryos.

In Humans, Clear Gender Differentiation Occurs Not at Fertilization, but After