Replicated Chromosome Structure in Prophase

Steps:

• In prophase of mitosis, DNA has replicated in S phase, forming two identical sister chromatids joined at the centromere.
• Each chromatid contains one double-stranded DNA molecule, so two chromatids mean four polynucleotide strands total.
• The chromosome has two telomeres, one at each end, regardless of replication.
• Each chromatid has its own centromeric region, counted as two centromeres in this context, with two visible chromatids.

Why C is correct:

• Matches the replicated state: two centromeres (one per chromatid), two chromatids, four polynucleotide strands (two per DNA molecule), and two telomeres per chromosome definition.

Why the others are wrong:

• A: Describes unreplicated chromosome (one centromere, zero chromatids, two strands); incorrect for prophase.
• B: Lists zero chromatids, but sister chromatids are visible and condensing in prophase.
• D: Lists two polynucleotide strands (unreplicated) and four telomeres (impossible, as chromosome has only two ends).

Final answer: C