AP BIOLOGY

Detailed explanation-1: -The two “sister” chromatids are joined at a constricted region of the chromosome called the centromere. During cell division, spindle fibers attach to the centromere and pull each of the sister chromatids to opposite sides of the cell. Soon after, the cell divides in two, resulting in daughter cells with identical DNA.

Detailed explanation-2: -During prophase stage, sister chromatids are observed to be attached together at centromere. At metaphase stage, chromosomes align singly on the equator and spindle fibres begin to attach to the kinetochores proteins found at centromere of the sister chromatids.

Detailed explanation-3: -During DNA duplication in the S phase, each chromosome is replicated to produce two identical copies, called sister chromatids, that are held together at the centromere by cohesin proteins. Cohesin holds the chromatids together until anaphase II.

Detailed explanation-4: -Sister Chromatids Are Joined Together at Centromeres In addition to their kinetochore-related function, centromeres perform another essential role in mitosis by serving as the sites of sister chromatid cohesion. For accurate mitoses, sister chromatids must remain attached until the spindle checkpoint has been passed.

Detailed explanation-5: -After DNA is replicated each chromosome consists of paired sister chromatids held together by cohesin.