3.24 b

3.24 b understand that division of a diploid cell by mitosis produces 2 cells which contain identical sets of chromosomes.

copying chromosomes is called DNA replication.
in this process each chromosome undergoes a copying process to form an identical copy of itself with the same genes and alleoles. these 2 copies are held together by a 'centomere'
while the chromosomes are in a copied pair held together by a centomere we refer to them as a 'pair of chromatids'
process of DNA replication takes place inside the nucleus while the nucleus is stil intact. this is the 'interphase' of the cell cycle.