In the absence of sufficient quantities of 5-alpha-reductase,
A) 5-alpha-dihydrotestosterone is not converted into testosterone, and external genitalia are not masculinized in the fetus.
B) testosterone is not converted into 5-alpha-dihydrotestosterone, and external genitalia are not masculinized in the fetus.
C) 5-alpha-dihydrotestosterone is not converted into testosterone, and internal organs are not masculinized in the fetus.
D) testosterone is not converted into 5-alpha-dihydrotestosterone, and internal organs are not masculinized in the fetus.

Question

Quizplus · Accepted Answer

5-alpha-reductase is the enzyme that converts testosterone to its more potent form, 5-alpha-dihydrotestosterone. In the absence of sufficient quantities of 5-alpha-reductase, testosterone is not converted into 5-alpha-dihydrotestosterone, which is necessary for the masculinization of external genitalia in the fetus. Therefore, choice B is the correct answer.

In the Absence of Sufficient Quantities of 5-Alpha-Reductase