What is a chromatid?

A chromatid is defined as one half of a duplicated chromosome. This terminology is essential in understanding the structure of chromosomes during the cell cycle, particularly during the processes of cell division like mitosis and meiosis.

When a cell prepares to divide, its chromosomes are duplicated in the S phase of interphase. Each chromosome then consists of two identical sister chromatids, which are held together at a region called the centromere. During cell division, these sister chromatids are separated and distributed into two daughter cells, ensuring that each new cell receives an identical set of genetic material.

Understanding the role of chromatids is crucial for grasping how genetic information is passed on during cell division, as well as recognizing the stages of the cell cycle.