ABT Reproductive and Developmental Toxicology

Question 1

Which period of prenatal development is most sensitive to teratogenic agents causing structural malformations?

Accepted Answer

Weeks 3–8 (organogenesis)

Answer

Weeks 1–2 (pre-implantation)

Answer

Weeks 9–38 (fetal period)

Answer

Week 40 (peripartum)

Question 2

Thalidomide caused phocomelia (limb reduction defects) when taken during which gestational window?

Accepted Answer

Days 27–40

Answer

Days 1–14

Answer

Weeks 12–20

Answer

Third trimester

Question 3

The Reproductive and Developmental Toxicant classification system in the US uses which regulatory framework?

Accepted Answer

GHS/OSHA Hazard Communication Standard

Answer

REACH (EU)

Answer

Prop 65 / California Safe Drinking Water Act

Answer

EPA Developmental Neurotoxicity Guidelines (DNT)

Question 4

Which drug is a known human teratogen classified FDA Category X and causes fetal hydantoin syndrome?

Accepted Answer

Phenytoin

Answer

Valproic acid

Answer

Carbamazepine

Answer

Lithium

Question 5

Which mechanism explains the selective vulnerability of the fetal brain to methylmercury neurotoxicity?

Accepted Answer

Incomplete blood-brain barrier and active neuronal migration in the developing CNS

Answer

Immature liver conjugation of mercury

Answer

Higher renal clearance of mercury in fetuses

Answer

Greater mercury intake via amniotic fluid

Question 6

Which endocrine-disrupting chemical is associated with clear cell adenocarcinoma of the vagina in daughters of women treated during pregnancy?

Accepted Answer

Diethylstilbestrol (DES)

Answer

Bisphenol A (BPA)

Answer

DDT

Answer

Atrazine