Which correctly describes sister chromatids? (1 point)
A. • They form during metaphase when DNA is being replicated.
B. • They are part of the lined-up chromosomes in mitosis.
C. • They are the daughter cells that form during cell replication.
D. • They make up the mitotic spindle within the cell.
B. • They are part of the lined-up chromosomes in mitosis.
B. • They are part of the lined-up chromosomes in mitosis.
To determine the correct description of sister chromatids, we need to understand what sister chromatids are and where they are involved in the cell cycle.
Sister chromatids are two identical copies of a single chromosome that are attached to each other at the centromere. They are formed during DNA replication in the S phase of the cell cycle. So, let's evaluate each option based on this information:
A. They form during metaphase when DNA is being replicated.
This option is not correct. Sister chromatids are formed during the S phase of the cell cycle, not during metaphase.
B. They are part of the lined-up chromosomes in mitosis.
This option correctly describes sister chromatids. During mitosis, sister chromatids are lined up along the equator of the cell and then separated to form two identical sets of chromosomes in the newly formed daughter cells.
C. They are the daughter cells that form during cell replication.
This option is not correct. Sister chromatids are not the daughter cells that form during cell replication. Instead, they are the replicated copies of a single chromosome.
D. They make up the mitotic spindle within the cell.
This option is not correct. The mitotic spindle is made up of microtubules and is responsible for separating sister chromatids during mitosis.
Based on the above analysis, the correct description of sister chromatids is:
B. They are part of the lined-up chromosomes in mitosis.