Reproductive pharmacology screening: aphrodisiacs and antifertility agents MCQs With Answer

Introduction

This quiz collection covers key concepts and screening methods in reproductive pharmacology, focusing on aphrodisiacs and antifertility agents relevant to M.Pharm students. Questions emphasize experimental models (male and female behavioral assays, apomorphine-induced penile erection, anti‑implantation tests), in vitro screens (sperm motility, E‑SCREEN), hormonal and anatomical endpoints (estrous cycle, serum estradiol, implantation sites), and regulatory species selection and safety parameters. Each MCQ is crafted to test both practical screening design and mechanistic understanding, helping students prepare for advanced coursework and preclinical study planning. Answers are provided to reinforce learning and clarify common experimental interpretations.

Q1. Which animal model is classically used to quantify male sexual behavior by measuring mount latency, intromission frequency and ejaculation latency?

• Male rat sexual behavior test (mount, intromission, ejaculation)
• Apomorphine‑induced penile erection in mice
• Vaginal smear estrous cycle monitoring in female rats
• Post‑coital antifertility assay in rabbits

Correct Answer: Male rat sexual behavior test (mount, intromission, ejaculation)

Q2. In the apomorphine‑induced penile erection test, which primary outcome indicates a pro‑erectile effect of a test compound?

• Increased number of penile erections
• Decreased mount latency in females
• Increased number of intromissions
• Prolonged estrous phase

Correct Answer: Increased number of penile erections

Q3. Which preclinical method is specifically designed to detect anti‑implantation activity of a compound?

• Anti‑implantation test in rodents during the implantation window
• Sperm motility assay using CASA
• Uterotrophic assay in immature females
• Lordosis quotient measurement

Correct Answer: Anti‑implantation test in rodents during the implantation window

Q4. What is the primary mechanism of action of mifepristone (RU‑486) used as a medical abortifacient?

• Progesterone receptor antagonist
• Estrogen receptor agonist
• GnRH receptor agonist
• Aromatase inhibitor

Correct Answer: Progesterone receptor antagonist

Q5. Which in vitro method is most appropriate for screening spermicidal activity by measuring motility?

• Sperm motility assay using CASA (computer‑assisted sperm analysis)
• Vaginal cytology smear
• Uterine weight measurement
• Serum testosterone assay

Correct Answer: Sperm motility assay using CASA (computer‑assisted sperm analysis)

Q6. During vaginal cytology for estrous cycle monitoring in rats, which cell type predominates in the estrus phase?

• Cornified epithelial cells
• Leukocytes
• Nucleated epithelial cells
• Spermatozoa

Correct Answer: Cornified epithelial cells

Q7. How is the lordosis quotient (LQ) defined when assessing female sexual receptivity in rodents?

• Number of lordosis responses per number of mounts × 100
• Time to first mount measured in seconds
• Number of intromissions per ejaculation
• Uterine weight increase compared to control

Correct Answer: Number of lordosis responses per number of mounts × 100

Q8. Which serum hormone measurement is most informative for assessing ovarian endocrine effects of a test compound in females?

• Serum estradiol
• Serum creatinine
• Alanine aminotransferase (ALT)
• Thyroid stimulating hormone (TSH)

Correct Answer: Serum estradiol

Q9. The primary contraceptive action of levonorgestrel when used as an emergency contraceptive is:

• Inhibition or delay of ovulation
• Induction of abortion of an established pregnancy
• Increased sperm motility
• Promotion of endometrial receptivity to implantation

Correct Answer: Inhibition or delay of ovulation

Q10. Which class of drugs is used to suppress spermatogenesis hormonally as a potential male antifertility approach?

• GnRH analogs (agonists or antagonists)
• PDE5 inhibitors
• Dopamine agonists
• Oxytocin antagonists

Correct Answer: GnRH analogs (agonists or antagonists)

Q11. Which drug is commonly used as a positive control in pharmacological aphrodisiac screening due to its pro‑erectile effects?

• Sildenafil citrate
• Mifepristone
• Levonorgestrel
• Clomiphene citrate

Correct Answer: Sildenafil citrate

Q12. Which active ingredient is most frequently formulated in over‑the‑counter spermicides?

• Nonoxynol‑9
• Miconazole nitrate
• Lidocaine
• Benzalkonium chloride

Correct Answer: Nonoxynol‑9

Q13. Which method is standard for determining sperm concentration during male fertility screening?

• Sperm count using a hemocytometer
• Vaginal lavage cytology
• Counting implantation sites
• Measuring corpora lutea

Correct Answer: Sperm count using a hemocytometer

Q14. In anti‑implantation studies, which direct endpoint most clearly indicates antifertility activity?

• Reduced number of implantation sites per uterus
• Increased litter size at term
• Prolonged gestation length
• Increased number of corpora lutea

Correct Answer: Reduced number of implantation sites per uterus

Q15. Regulatory reproductive toxicity studies commonly require which two species for generalization of results?

• Rat and rabbit
• Mouse and dog
• Non‑human primate and cat
• Guinea pig and hamster

Correct Answer: Rat and rabbit

Q16. In male sexual behavior screening, which change is interpreted as an increase in sexual potency?

• Reduced mount latency
• Elevated uterine weight
• Decreased sperm count
• Prolonged estrous cycle in females

Correct Answer: Reduced mount latency

Q17. For anti‑implantation screening in rats, the critical implantation window commonly used for dosing is approximately which days post coitum?

• Days 4–6 post coitum
• Days 1–2 post coitum
• Days 10–12 post coitum
• Days 14–16 post coitum

Correct Answer: Days 4–6 post coitum

Q18. Which in vitro assay is widely used to detect estrogenic activity by measuring proliferation of estrogen‑sensitive cells?

• E‑SCREEN assay using MCF‑7 cell proliferation
• Sperm chromatin structure assay
• Comet assay for DNA damage
• Uterotrophic bioassay in immature rodents

Correct Answer: E‑SCREEN assay using MCF‑7 cell proliferation

Q19. Which bioassay quantifies the uterotropic (estrogenic) response in immature or ovariectomized rodents?

• Uterotrophic assay
• Vaginal smear assay
• Sperm motility assay
• Implantation index

Correct Answer: Uterotrophic assay

Q20. In developmental and reproductive toxicology, which fetal finding is most directly indicative of teratogenicity?

• External malformations detected in fetuses
• Elevated maternal blood glucose
• Increased maternal ALT levels
• Altered maternal blood pressure

Correct Answer: External malformations detected in fetuses

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