Question

Why is DNA polymerase unable to initiate new strand synthesis on its own?

Options

• It can only add nucleotides to an existing 3′-OH group

• It cannot bind to the origin of replication

• It is unable to break hydrogen bonds

• It lacks the ability to recognise the template strand

Answer 1

DNA polymerase requires a pre-existing 3′-OH group to add nucleotides. It cannot initiate synthesis de novo (from scratch), which is why primase synthesises an RNA primer to provide this essential 3′-OH end for DNA polymerase to begin elongation.