kromatid

Kromatid, often referred to in English as chromatid, is one of the two identical copies of a chromosome that are produced when a chromosome is replicated during the S phase of the cell cycle. The two kromatids are held together at the centromere and together form a duplicated chromosome, sometimes described as sister chromatids.

Each kromatid contains a complete copy of the chromosome’s DNA sequence. After replication, cohesin proteins maintain the connection between the two chromatids until they are ready to be separated. In mitosis and in meiosis II, the sister kromatids are ultimately pulled apart and segregated into daughter cells, ensuring that each new cell receives an identical set of chromosomes.

During the stages of cell division, kromatids condense into more compact structures, align at the metaphase plate, and are separated during anaphase. The separation event is triggered by the cleavage of cohesin complexes, allowing chromatids to move to opposite poles as individual chromosomes.

Kromatids should not be confused with homologous chromosomes, which are paired chromosomes inherited from different parents during meiosis I. Recombination and crossing over can occur between non-sister kromatids within a homologous pair, contributing genetic variation. However, for the most part, sister kromatids carry identical genetic information until they are separated during cell division.