The nucleus contains chromosomes, these are made from the molecule DNA.
There are 46 chromosomes in every human body cell and they are arranged in pairs. (these are called homologous pairs)
Each pair consists of one maternal chromosome and one paternal chromosome.
There are 23 pairs in humans. Each individual chromosome is a long length of DNA, some sections of DNA are the instructions to build proteins; these are genes.
Genes are short lengths of DNA which code for specific amino acids
Interphase is the longest phase, during which DNA replicates to form two identical copies.
The cell cycle is the series of events that occur between one cell division and another.
DNA synthesis occurs during interphase when DNA replication takes place.