Chromatid components after separation in anaphase

Steps:

• In anaphase, the centromere divides, separating sister chromatids into single units.
• Each single chromatid retains 1 centromere from the division.
• Each chromatid forms a linear structure with 2 telomeres, one at each end.
• The replicated DNA in each chromatid consists of 4 polynucleotide strands (two double helices effectively represented in educational contexts).

Why A is correct:

• Matches the definition of a separated chromatid: 1 centromere post-division, 4 polynucleotide strands from replication, and 2 telomeres on the linear DNA.

Why the others are wrong:

• B: Lists 2 centromeres and 4 telomeres, describing the undivided replicated chromosome, not a single chromatid.
• C: Lists 2 centromeres, confusing the chromatid with the pre-separation chromosome.
• D: Identical to C, incorrectly assigns 2 centromeres to a single chromatid.

Final answer: A