What is an An X-Shaped structure that is a chromosome and its exact copy?

An X-shaped structure that represents a chromosome and its exact copy is known as a sister chromatid. During cell division, specifically in the S phase of the cell cycle, each chromosome is duplicated, resulting in two identical sister chromatids joined at a region called the centromere. These sister chromatids are separated during mitosis or meiOSis, ensuring that each daughter cell receives an identical set of chromosomes.