AP BIOLOGY

Detailed explanation-1: -A chromatid is one of the two identical halves of a chromosome that has been replicated in preparation for cell division. The two “sister” chromatids are joined at a constricted region of the chromosome called the centromere.

Detailed explanation-2: -Before anaphase begins, the replicated chromosomes, called sister chromatids, are aligned at along the equator of the cell on the equatorial plane. The sister chromatids are pairs of identical copies of DNA joined at a point called the centromere.

Detailed explanation-3: -As long as the sister chromatids are connected at the centromere, they are still considered to be one chromosome. However, as soon as they are pulled apart during cell division, each is considered a separate chromosome.

Detailed explanation-4: -They are called sister chromatids because all the genes and to be specific all the alleles are exactly the same because they are identical copies (Figure 1). Sister Chromatids = Replicated Chromosomes Attached at the Centromere.

Detailed explanation-5: -Sister chromatids are two identical copies of the same chromosome formed by DNA replication, attached to each other by a structure called the centromere. During cell division, they are separated from each other, and each daughter cell receives one copy of the chromosome.