Chromatids

Definition

Chromatids are identical halves of a duplicated chromosome formed during cell division. Each chromatid contains one DNA molecule and is joined to its sister chromatid by a centromere.

5 Must Know Facts For Your Next Test

1. Chromatids are formed during the S phase of the cell cycle when DNA replication occurs.
2. Sister chromatids are separated into individual chromosomes during anaphase of mitosis.
3. During meiosis, homologous chromosomes pair up and exchange segments between non-sister chromatids in a process called crossing over.
4. Each chromatid becomes an independent chromosome once it is separated from its sister chromatid.
5. The point at which sister chromatids are held together is known as the centromere.

Review Questions

• At what stage of the cell cycle do chromatids form?
• What happens to sister chromatids during anaphase of mitosis?
• What process involves the exchange of genetic material between non-sister chromatids?

Related terms

Centromere:

The region where two sister chromatids are joined together.

Mitosis: A type of cell division resulting in two daughter cells with identical genetic material.

Meiosis: A type of cell division that reduces the chromosome number by half, creating four haploid cells.