The chromatin in interphase and in M phase

Correct Answer: C

Rationale: Chromatin is decondensed in interphase (for gene expression) and condensed in M phase (mitosis, for segregation). 'C' (Decondensed, Condensed) is correct. Rationale: Interphase chromatin is diffuse to allow transcription, while M phase (prophase to metaphase) condenses chromosomes into visible, compact structures for division.

Correct Answer: B

Rationale: Alpha satellite DNA is at the centromere (B). Rationale: These repetitive sequences define the centromere, aiding kinetochore attachment, distinct from telomeres or p-arms of acrocentrics.

Correct Answer: B

Rationale: SRY gene (B) causes 46, XX males. Rationale: SRY translocation to X or autosome in XX individuals triggers male development; AZFa affects spermatogenesis, not sex determination.

Correct Answer: A

Rationale: Complete mole (A) has no fetus. Rationale: All-paternal DNA (46, XX/YY) forms placental tissue only; partial moles (triploid) may have fetal remnants.

Correct Answer: B

Rationale: Multifactorial diseases involve genetic and environmental factors (A) and include MS, diabetes, and cancer (C), but late-onset in one person doesn’t inherently increase sibling risk unless shared factors persist (B is not typical). Rationale: Multifactorial inheritance implies polygenic and environmental interplay, not age-specific sibling risk unless familial clustering is evident.