How many chromosomes does a cell have at Anaphase if it starts with 4 chromosomes during G1 phase?

A cell starting with 4 chromosomes during the G1 phase undergoes several key processes during the cell cycle, specifically DNA replication during the S phase, where each chromosome is duplicated. As a result, by the time the cell reaches anaphase, which is part of mitosis, the duplicated chromosomes have already formed sister chromatids.

During anaphase, the sister chromatids are pulled apart and move toward opposite poles of the cell. Even though the chromatids separate during this stage, the total number of chromatid structures is essential for understanding chromosome count. Since each of the original 4 chromosomes has been replicated into 2 sister chromatids, the cell will have a total of 8 chromatids at anaphase. However, because chromosomes are typically counted based on the number of centromeres, which are the regions where sister chromatids are joined, the correct interpretation for chromosome count during anaphase is that there are still 8 chromatid structures that functionally represent 8 chromosomes as they move towards the poles.

Thus, the answer is that at the anaphase stage, the total number of chromosomal structures is counted as 8.