Biological Systems MCAT Practice Exam

Which hormone does the testes produce to inhibit the development of the Müllerian ducts?

1. Follicle-stimulating hormone (FSH)

2. Luteinizing hormone (LH)

3. Müllerian inhibiting factor (MIF)

4. Estrogen

The correct answer is: Müllerian inhibiting factor (MIF)

The correct response is grounded in the role of Müllerian inhibiting factor (MIF), also known as Anti-Müllerian Hormone (AMH), which is produced by the Sertoli cells in the testes. MIF plays a crucial role during male embryonic development by inhibiting the formation of the Müllerian ducts, which are precursors to female reproductive structures. In the presence of MIF, the Müllerian ducts regress, allowing for the development of male reproductive structures such as the vas deferens and seminal vesicles, while preventing female structures from forming. This is an essential aspect of sexual differentiation in embryos, with MIF signaling the body to follow a male developmental pathway. In contrast, other hormones such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are involved in the regulation of spermatogenesis and testosterone production, but they do not directly influence the development of the Müllerian ducts. Estrogen, typically associated with the development of female characteristics, does not play a role in inhibiting the Müllerian ducts in males. Thus, MIF is the specific hormone that accomplishes the task of inhibiting Müllerian duct development in male embryos.