§-Quick questions
NSWBiologyModule 5: Heredity
Quick questions on DNA replication explained: HSC Biology Module 5
8short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What is 1. Unwinding?Show answer
The enzyme helicase breaks the hydrogen bonds between base pairs, separating the double helix into two single strands at the replication fork.
What is 2. Priming?Show answer
Primase synthesises a short RNA primer on each single strand, giving DNA polymerase a free 3'-OH group to extend from.
What is 3. Elongation?Show answer
DNA polymerase reads each template strand in the 3' to 5' direction and adds complementary free nucleotides to the growing daughter strand in the 5' to 3' direction.
What is 4. Ligation?Show answer
DNA ligase joins the Okazaki fragments into one continuous strand.
What are wrong base pairs?Show answer
A pairs with T (DNA) or U (RNA). G pairs with C. Get this wrong and you lose 1-2 marks immediately.
What is name enzymes precisely?Show answer
Helicase, primase, DNA polymerase, ligase - in order, with one role each. A generic "an enzyme unzips it" caps a description answer.
What are show direction on diagrams?Show answer
If you draw the fork, mark 5' and 3' ends and an arrow on each new strand. Directionality is where marks are won or lost.
What is link replication to the bigger picture?Show answer
For IQ2, be ready to connect replication fidelity to mitosis, meiosis and continuity of species - examiners reward the synoptic link.