Sertoli cells of fetus testis secretes -

Ans. is 'd' i.e., Mullerian inhibiting substance o Fetal testis secretes mullerian inhibiting substance produced by sertoli cells which acts locally as a paracrine factor to cause mullerian duct regression. Mullerian duct regression completes by 9 to 10 weeks' gestation, which is much before testosterone secretion has commenced.o Because mullerian inhibiting substance acts locally near its site of formation, the mullerian duct on that side would persist, and the uterus and fallopian tube would develop on that sideo Leydig cells in fetal testis are the cellular site of testosterone synthesis.