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: -A pair of sister chromatids is called a dyad. Once sister chromatids have separated (during the anaphase of mitosis or the anaphase II of meiosis during sexual reproduction), they are again called chromosomes, each having the same genetic mass as one of the individual chromatids that made up its parent.

Detailed explanation-3: -Chromosomes have proteins called histones that bind to DNA. DNA has two strands that twist into the shape of a spiral ladder called a helix. DNA is made up of four building blocks called nucleotides: adenine (A), thymine (T), guanine (G), and cytosine (C).

Detailed explanation-4: -Duplicated chromosomes are referred to as sister chromatids. Sister chromatids represent identical DNA chromosomes that will be separated during cell division to ensure each new cell receives the full amount of DNA in order to survive and carry out their normal metabolic functions.

Detailed explanation-5: -A replicated chromosome (or equivalently, a duplicated chromosome) contains two identical chromatids, also called sister chromatids. The difference between a duplicated chromosome and a chromatid, strictly speaking, is that a chromosome contains two chromatids that are joined at a structure called a centromere.