Which of the following human triploid is possible to be found in adults:

Correct Answer: B

Rationale: Triploidy is incompatible with adult life (B). Rationale: 69, XXY (not listed) or similar triploids (3n) occur but are lethal or result in miscarriage. 92 (4n) or 23 (n) don’t fit triploidy (3n=69). Adults don’t survive triploidy.

Correct Answer: A

Rationale: M phase (mitosis) is the shortest, typically 1–2 hours in a 24-hour cycle. 'A' is correct. Rationale: G1, S, and G2 (interphase) last longer (hours each), while GO is a quiescent state, not a timed phase. Mitosis is rapid, with visible stages like metaphase lasting minutes.

Correct Answer: D

Rationale: Erythrocytes (D) cannot be used for karyotyping as they lack nuclei. Rationale: Karyotyping requires dividing cells with chromosomes; chorionic villi, lymphocytes, and bone marrow provide mitotic cells, but mature erythrocytes are enucleated.

Correct Answer: A

Rationale: Telomeres (A) protect chromosome ends and prevent fusion. Rationale: TTAGGG repeats cap chromosomes, stabilizing them; centromeres attach spindles, subtelomeres are adjacent but not protective.

Correct Answer: C

Rationale: Reciprocal t(9;22) (C) causes CML (Philadelphia chromosome). Rationale: BCR-ABL1 fusion drives myeloid proliferation; Robertsonian involves acrocentrics (e.g., 14;21), not 9;22.