Reproductive toxicology: male and female studies MCQs With Answer

Introduction: Reproductive toxicology: male and female studies MCQs With Answer is a focused review resource tailored for M.Pharm students preparing for exams and research in reproductive toxicology. This blog offers concise, high-yield multiple-choice questions covering experimental designs, regulatory guidelines (OECD/ICH), endpoints for fertility and developmental toxicity, assay techniques (sperm analysis, estrous cycle evaluation, implantation counts), and interpretation of morphological and biochemical biomarkers. Emphasis is on study selection, dosing strategies, statistical considerations, and juvenile/perinatal evaluations. The questions are crafted to deepen conceptual understanding and application in preclinical toxicology, helping students link mechanistic knowledge with practical screening protocols used in male and female reproductive safety assessment.

Q1. What is the primary objective of a one-generation reproductive toxicity study (OECD TG 415) in preclinical testing?

• To evaluate acute toxicity following a single high dose
• To assess effects on fertility, embryonic development, and early postnatal growth within one generation
• To determine the pharmacokinetic profile of a compound during pregnancy
• To replace full two-generation studies for regulatory submission

Correct Answer: To assess effects on fertility, embryonic development, and early postnatal growth within one generation

Q2. Which parameter is most commonly used as an indicator of male reproductive toxicity in rodents?

• Changes in estrous cycle length
• Sperm count, motility, and morphology
• Number of implantation sites in females
• Plasma glucose concentration

Correct Answer: Sperm count, motility, and morphology

Q3. In developmental (embryo-fetal) toxicity studies, exposure during which period is most critical for detecting teratogenic effects in rodents?

• Pre-implantation period only
• Organogenesis period
• Late fetal growth period
• Postnatal lactation period

Correct Answer: Organogenesis period

Q4. Nipple/areola retention in male rat pups is used as an indicator of disruption in which hormonal pathway?

• Thyroid hormone signaling
• Androgen signaling during sexual differentiation
• Prolactin secretion from the pituitary
• Estrogen synthesis in the placenta

Correct Answer: Androgen signaling during sexual differentiation

Q5. Which OECD guideline specifically addresses two-generation reproductive toxicity studies?

• OECD TG 421
• OECD TG 414
• OECD TG 416
• OECD TG 443

Correct Answer: OECD TG 416

Q6. Anogenital distance (AGD) measurement in neonates is primarily used to assess:

• Cardiac development
• Effects on thyroid function
• Androgenic/anti-androgenic disruption during development
• Neuromuscular maturation

Correct Answer: Androgenic/anti-androgenic disruption during development

Q7. Which of the following is a critical design element for male fertility studies evaluating spermatogenesis?

• Exposure only during gestation
• Exposure for at least one full spermatogenic cycle prior to mating
• Exposure limited to lactation period
• Single dose administration on the day of mating

Correct Answer: Exposure for at least one full spermatogenic cycle prior to mating

Q8. In pre- and post-natal development (PPND) studies, which endpoints are routinely evaluated in F1 offspring?

• Only body weight at birth
• Neurobehavioral milestones, growth, sexual maturation, and reproductive performance
• Blood pressure and renal clearance only
• Adult pharmacokinetics at 2 years of age

Correct Answer: Neurobehavioral milestones, growth, sexual maturation, and reproductive performance

Q9. Which assay is specifically designed to detect chromosomal aberrations in germ cells and can be part of reproductive toxicology assessment?

• Micronucleus test in peripheral blood
• Dominant lethal assay
• Comet assay in liver cells
• Ames test

Correct Answer: Dominant lethal assay

Q10. Which female reproductive parameter is routinely monitored in rodents to assess ovarian function and potential toxicity?

• Daily estrous cycle staging by vaginal cytology
• Serum creatinine measurement
• Pulse oximetry readings
• Fur color changes

Correct Answer: Daily estrous cycle staging by vaginal cytology

Q11. Which result in embryo-fetal skeletal staining (e.g., Alizarin Red) suggests delayed ossification due to maternal treatment?

• Increased number of ossified centers compared to control
• Reduced ossification centers and persistence of cartilage in expected ossified regions
• Complete absence of any skeletal elements
• Only soft tissue abnormalities with normal skeletal pattern

Correct Answer: Reduced ossification centers and persistence of cartilage in expected ossified regions

Q12. In a two-generation study, which endpoint distinguishes parental (P) from F1 parental reproductive performance?

• Water consumption in cages
• Fertility indices, mating success, and litter size across generations
• Plasma albumin levels in pups only
• Time to first estrus in the P generation only

Correct Answer: Fertility indices, mating success, and litter size across generations

Q13. Which hormone assay is most informative for evaluating Leydig cell function in male reproductive toxicology?

• Thyroid stimulating hormone (TSH)
• Serum testosterone concentration
• Serum cortisol concentration
• Prolactin levels only

Correct Answer: Serum testosterone concentration

Q14. What is the significance of implantation site counting at necropsy in developmental toxicity studies?

• It indicates maternal liver toxicity only
• It provides data on pre- and post-implantation loss and embryotoxic effects
• It measures placental hormone secretion directly
• It replaces the need to examine fetal external malformations

Correct Answer: It provides data on pre- and post-implantation loss and embryotoxic effects

Q15. Which of the following best describes the dominant lethal test endpoint?

• Measurement of blood pressure fluctuations in males
• Assessment of heritable mutations that result in embryonic death following paternal exposure
• Evaluation of maternal behavior alterations postpartum
• Measurement of neonatal brain weight only

Correct Answer: Assessment of heritable mutations that result in embryonic death following paternal exposure

Q16. When interpreting altered estrous cyclicity in treated females, which complementary assessment helps clarify ovarian vs central causes?

• Measurement of kidney histology
• Serum gonadotropins (LH, FSH) and estradiol levels along with ovarian histopathology
• Assessment of fur growth rate
• Only measuring body weight is sufficient

Correct Answer: Serum gonadotropins (LH, FSH) and estradiol levels along with ovarian histopathology

Q17. In regulatory embryo-fetal development studies, which species is commonly used in addition to rodents for improved translational relevance?

• Zebrafish only
• Non-rodent species such as rabbits
• Fruit flies (Drosophila)
• Guinea pigs exclusively for all programs

Correct Answer: Non-rodent species such as rabbits

Q18. Which finding in male reproductive organs at histopathology is most suggestive of direct testicular toxicity?

• Hepatocellular vacuolation
• Spermatogenic cell depletion and tubular atrophy
• Pulmonary alveolar hyperplasia
• Renal tubular dilation

Correct Answer: Spermatogenic cell depletion and tubular atrophy

Q19. Which statistical approach is most appropriate for analyzing litter-based endpoints to avoid pseudo-replication?

• Treat each pup as an independent sample without adjustment
• Use the litter as the statistical unit or apply mixed-effects models accounting for litter clustering
• Ignore litter effects and pool pups across litters
• Compare only the largest litters across groups

Correct Answer: Use the litter as the statistical unit or apply mixed-effects models accounting for litter clustering

Q20. Which developmental toxicity marker measured in pups is particularly sensitive for detecting endocrine disruption affecting sexual differentiation?

• Righting reflex latency only
• Anogenital distance and nipple retention (male pups)
• Blood urea nitrogen levels
• Fur color at weaning

Correct Answer: Anogenital distance and nipple retention (male pups)

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