Question

Two sister chromatids are joined at the centromere prior to meiosis. Which statement is correct? a. These chromatids make up a diploid chromosome. b. Barring mutation, the two sister chromatids must be identical. c. The cell that contains these sister chromatids must be haploid.

Answer 1

Answer:

b. Barring mutation, the two sister chromatids must be identical.

Explanation:

Prior to meiosis, the DNA is replicated so cells enter division with all its chromosomes having two sister chromatids united at the centromere.

DNA replication is semiconservative: the original DNA strands are separated and new strands are synthesized using the original ones as templates. As a result, each sister chromatid is made of one original DNA strand and a newly synthesized DNA strand, and both should be identical to each other.