Question

review this diagram; select the response that best describes label #2.

a sister chromosomes
b centromere
c chromatid
d chromatin

question 15
during the cell cycle, the cell replicates dna. this step occurs _
a during mitosis.
b between interphase and mitosis.
c after telophase.
d during interphase.

Explanation:

For the first question:

• Sister chromosomes (a) is incorrect. Sister chromatids are the two - identical halves of a replicated chromosome.
• Centromere (b) is correct. The centromere is the region of a chromosome where the two sister chromatids are held together.
• Chromatid (c) is incorrect. Chromatids are the individual strands (label 4).
• Chromatin (d) is incorrect. Chromatin is the complex of DNA and proteins that condenses to form chromosomes.

For the second question:

• DNA replication does not occur during mitosis (a). Mitosis is for cell division.
• DNA replication occurs during interphase (d). The cell cycle has interphase (where DNA replication occurs in the S - phase) and mitosis. It is not between interphase and mitosis (b) as interphase includes the S - phase (DNA replication phase). After telophase (c) is part of mitosis and DNA replication is already done before mitosis.

Answer:

First question: b. centromere
Second question: d. during interphase