In the routinely performed karyotype (G-banding). Which of the following would you expect to have more clinical impact and lead to a disease?

Correct Answer: D

Rationale: Deletion of a light band (D) has more impact. Rationale: Light bands (euchromatin) are gene-rich; deletions (loss of function) often cause disease (e.g., 5p-). Duplications (A, B repeated) may be milder; single-band changes can matter (C false).

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.

Correct Answer: B

Rationale: Digynic (B, maternal triploidy) fits. Rationale: 2 maternal + 1 paternal sets (69, XXX/XXY) cause small fetus, macrocephaly; diandric has large placenta.