Final answer:
During DNA replication, each chromosome in a cell is duplicated. This results in each cell having two copies of each chromosome, referred to as sister chromatids.
Step-by-step explanation:
During DNA replication, each chromosome in a cell is duplicated. This results in each cell having two copies of each chromosome, referred to as sister chromatids. So if a cell has 24 chromosomes before DNA replication, it would have 48 chromosomes after replication (24 pairs of sister chromatids).