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9.1 Sexual Differentiation — Test 1
Q1. The gene on the Y chromosome that initiates testis determination is:✓ SRY
Q2. Anti-Mullerian hormone (AMH) from the fetal testis causes:✓ Regression of the Mullerian (female) ducts
Q3. Testosterone is responsible for development of the:✓ Wolffian (male internal) ducts
Q4. Dihydrotestosterone (DHT) is required for development of the:✓ Male external genitalia and prostate
Q5. Feminization of external genitalia in a 46,XY individual can result from a mutation in:✓ 5alpha-reductase
Q6. Congenital adrenal hyperplasia (21-hydroxylase deficiency) in a genetic female causes:✓ Female pseudohermaphroditism (virilized external genitalia)
Q7. Complete androgen insensitivity (defective androgen receptor) in a 46,XY individual produces:✓ A female phenotype with testes and no uterus
Q8. Match each hormone/factor with its role in differentiation and choose the correct option.✓ A-ii, B-i, C-iii
Q9. In the absence of SRY (e.g. a normal 46,XX embryo), the gonad develops into:✓ An ovary
Q10. AMH is secreted by which testicular cell?✓ Sertoli cells
Q11. In 5alpha-reductase deficiency, at puberty there is often:✓ Virilization (rising testosterone acts on receptors)
Q12. The internal male ducts (epididymis, vas, seminal vesicles) develop from the:✓ Wolffian ducts under testosterone
Q13. In androgen insensitivity syndrome, why is there no uterus?✓ AMH from the testes still causes Mullerian regression
Q14. Genetic sex is determined by:✓ The sex chromosomes (presence/absence of Y/SRY)
Q15. The default developmental pathway (without androgens/AMH) is:✓ Female
Q16. Leydig cells contribute to male differentiation by secreting:✓ Testosterone
Q17. A 46,XX fetus exposed to excess androgens (e.g. CAH) will show:✓ Virilized external genitalia with female internal organs
Q18. The hormone that prevents the female (Mullerian) duct system in males is:✓ Anti-Mullerian hormone
Q19. Why do internal and external genitalia use different androgens (testosterone vs DHT)?✓ Different tissues require different androgen potency/conversion
Q20. The overall sequence of male sexual differentiation is:✓ SRY -> testis -> testosterone/AMH -> Wolffian development/Mullerian regression -> DHT for external genitalia