Any 3 below
You will need a orginal DNA template - this is used for the DNA polymerase to copy the DNA. DNA is a double stranded helix and each strand can be used as a template for replication free DNA nucleotides - a DNA nucleotide is made up of a base, phosphate and deoxyribose sugar. These are needed to synthesise new strands DNA polymerase - this is an enzyme which adds new nucleotides to a growing strand of DNA Primers - this is a short strand of DNA that binds to the strand and is a starting point for DNA synthesis. This indicates where DNA polymerase should begin replication