Nondisjunction in meiosis I happens between and in meiosis II it happens between

Correct Answer: B

Rationale: MI: homologous chromosomes; MII: sister chromatids (B). Rationale: MI separates homologs, MII splits chromatids, causing aneuploidy if nondisjunction occurs.

Correct Answer: B

Rationale: Umbilicated lesions (central depression) are characteristic of Molluscum contagiosum (B). Rationale: Pinworms (A) cause pruritus without nodules; lice (C) have nits; Shigella (D) and Streptococcus (E) cause discharge, not umbilicated lesions.

Correct Answer: D

Rationale: Topical estrogens (D) are the standard treatment for labial adhesions. Rationale: Estrogen separates fused labia by promoting epithelial growth; antibiotics (A, B) treat infection, not adhesions; oral estrogens (C) are less targeted.

Correct Answer: B

Rationale: Dysgerminomas, germ cell tumors, are linked to X-Y gonadal dysgenesis (B). Rationale: XY females (e.g., Swyer syndrome) have dysgenetic gonads prone to malignancy; Turner (C) and Noonan (A) involve XO or other defects, less associated.

Correct Answer: B

Rationale: Achondroplasia causes foramen magnum stenosis (B), leading to brainstem compression and apnea. Rationale: Skeletal dysplasia narrows this passage; dental issues (A) or hydrocephalus (C) are less direct causes.