A child person with clinical features that include: cardiovascular, brain with neurological, renal, gastrointestinal, respiratory, and skeletal malformations, craniofacial abnormalities such as prominent occiput, hand and feet anomalies including clenched hand. This patient is most probably affected with:

Correct Answer: A

Rationale: Trisomy 18 (Edwards syndrome, A) fits. Rationale: Clenched hands, multiple organ defects, and craniofacial issues (e.g., prominent occiput) are hallmark Edwards features. Down (B, D) lacks these specifics; Turner (C) differs (e.g., lymphedema).

Correct Answer: B

Rationale: Segregation involves homologous chromosomes separating; independent assortment involves different chromosomes assorting independently. 'B' is correct. Rationale: Mendel’s laws: segregation (alleles on homologs split in meiosis I), assortment (non-homologous chromosomes align randomly).

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.