Testis-determining factor
A) activates the Wolffian system.
B) inhibits the Müllerian system.
C) develops the primordial gonads into testes.
D) prevents the development of ovaries.

Question

Quizplus · Accepted Answer

The testis-determining factor (TDF) is a protein encoded by the SRY gene located on the Y chromosome. It plays a crucial role in sexual differentiation by initiating the development of male gonads (testes) in the early stages of embryonic development. TDF stimulates the differentiation of the indifferent gonads into testes and promotes the development of Sertoli cells and Leydig cells, which produce male hormones. Therefore, option C is correct.

Answer: A and B
 In addition to initiating the development of testes, TDF also has a negative effect on the development of female reproductive organs. TDF inhibits the development of the Müllerian duct system, which gives rise to the uterus, fallopian tubes, and part of the vagina in females. Conversely, it activates the development of the Wolffian duct system, which gives rise to the epididymis, vas deferens, and seminal vesicles in males. Therefore, options A and B are also correct.

Testis-Determining Factor