Explain how DNA is organised inside a human body cell and how it is used to produce proteins.

DNA is located in the nucleus of a human cell.
The DNA double helix is wrapped around histone proteins to form nucleosomes, which coil and condense to give the structure of chromosomes.
A gene is a defined segment of DNA that contains a sequence of bases.
The order of these bases is read as a code that specifies the sequence of amino acids in a protein.
During transcription the gene is copied to mRNA, which is then translated in the cytoplasm to join amino acids in the correct order, producing a functional protein.