NEET 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: -A pair of sister chromatids is called a dyad. A full set of sister chromatids is created during the synthesis (S) phase of interphase, when all the chromosomes in a cell are replicated.

Detailed explanation-3: -During S phase, each chromosome is replicated. This produces a second copy of each chromosome from the mother and a second copy of each chromosome from the father. These identical copies are known as sister chromatids.

Detailed explanation-4: -The sister chromatids are identical to one another and are attached to each other by proteins called cohesins. The attachment between sister chromatids is tightest at the centromere, a region of DNA that is important for their separation during later stages of cell division.

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