D1.1.1 DNA replication Flashcards
(20 cards)
What is the error rate of DNA replication?
About 1 in 10 billion bases.
During replication, what pairs with adenine (A)?
Thymine (T).
Why is complementary base pairing important in DNA replication?
It ensures that the new DNA strands are exact copies of the original.
What enzyme is responsible for unwinding the DNA double helix?
Helicase.
What does semi-conservative replication mean?
Each new DNA molecule consists of one original strand and one newly synthesized strand.
What is the error in DNA replication for a human cell with 6 billion base pairs?
On average, there are only 0.6 errors per replication cycle.
What experiment provided evidence for semi-conservative replication?
The Meselson-Stahl experiment.
Give an example of DNA replication in action.
When you cut your skin, DNA replication allows new cells to form and repair the wound.
Can DNA polymerase start a new strand from scratch?
No, it requires a short RNA primer to begin synthesis.
What is the proofreading function of DNA polymerase?
It detects and corrects mismatched bases during replication.
What is the role of DNA polymerase in DNA replication?
DNA polymerase adds nucleotides to the growing strand and forms covalent bonds between sugar and phosphate groups.
What are the biological significances of DNA replication?
- Reproduction
- Growth
- Tissue replacement.
What is the first step in the DNA replication process?
Unwinding the DNA double helix.
What happens if a nucleotide with the wrong base tries to pair?
It is rejected because the hydrogen bonds cannot form.
Why must DNA be replicated before a cell divides?
So that each daughter cell receives a complete set of genetic instructions.
What analogy is used to describe complementary base pairing?
A lock-and-key mechanism.
How does DNA replication ensure genetic continuity?
By producing exact copies of DNA, preserving genetic information across generations.
What is the role of free nucleotides during DNA replication?
They align with their complementary bases on the template strand to build a new strand.
What bonds does helicase break to unzip the DNA strands?
Hydrogen bonds between complementary base pairs.
What structure is formed by DNA polymerase between adjacent nucleotides?
A continuous sugar-phosphate backbone.
