3.24b Mitosis 2

- Copying the chromosomes is a process called "DNA replication"
- In the process, the chromosome undergoes a copying process to form an identical copy of itself with all the same genes and all the same alleles
- The copies are held together by a structure around the centre region called the "centromere"
- While the chromosomes are in a copied pair held together by a centromere, we refer to them as a "pair of chromatids"
- The process takes place inside the nucleus while the nucleus is still intact. We can't see this process. This is known as the "interphase" of the cell cycle.