Prior to mitosis and after s phase, each chromosome of a eukaryotic cell consists of a pair of identical structures . chromatinb. sister chromatidsc. sister chromosomes

Sister chromatids. (Ans. B)

Explanation:

Sister chromatids are defined as the identical chromatids formed by the DNA replication of the chromosome, both copies of chromatids are joint together by a centromere. A pair of chromatids are known as dyad.

A set of sister chromatids formed during the S phase or synthesis phase of interphase, while all the chromosomes present in a cell is replicated. During the process of mitosis, or second division of meiosis the two sister chromatids are gets separated from each other into two different daughter cells, and each cell receives one copy of the chromosomes.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

in addition to being able to metabolize, grow, digest food, and excrete wastes, what other functions must an organism perform if it is to survive? survival also depends on the ability to maintain one's boundaries, to move, to respond to stimuli, and to reproduce. oxygen is a survival need.