What are sister chromatids?

Sister chromatids are defined as identical copies of a chromosome that are formed during DNA replication. When a cell prepares to divide, it duplicates its chromosomes so that each daughter cell will have an identical set of genetic information. Each duplicated chromosome consists of two sister chromatids, which are held together at a region known as the centromere.

This structure is crucial for the accurate segregation of chromosomes during cell division. During mitosis or meiosis, the sister chromatids will separate, ensuring that each new cell receives the correct number of chromosomes. This process maintains genetic consistency across cells and is essential for proper growth, development, and reproduction.

In contrast, different forms of a gene refer to alleles, and chromosomes undergoing crossing-over involve the exchange of genetic material between homologous chromosomes, not sister chromatids. Cells produced from meiosis are the result of the division process but do not specifically describe sister chromatids. Thus, understanding the role and identity of sister chromatids is fundamental to grasping the mechanics of cell division in biology.