How does DNA replication occur?

DNA normally exists in the cell as a double-stranded structure, comprising of two complementary strands that are held together by hydrogen bonds.

DNA replication involves two main steps. Firstly, the enzyme HELICASE breaks the hydrogen bonds holding the two strands together, causing the strands to separate. Next, one DNA POLYMERASE enzyme binds to each strand of DNA and, using the strand as a template, generates a complementary strand.

Once this process is complete, there are now two double-stranded DNA molecules. This is known as SEMI-CONSERVATIVE replication, as each new DNA molecule is made up of one old strand and one new strand.

KH
Answered by Katharine H. Biology tutor

11838 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Describe how restriction enzymes are used to cut out DNA fragments


Describe the cardiac cycle?


Describe the series of events leading to atherosclerosis.


How is an electrical impulse transmitted through the heart?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning