2.2 - DNA Replication

Question 1

Before a nucleus divides its DNA must what?

Answer 1

Be replicated

Question 2

Why must the DNA be replicated?

Answer 2

To ensure that all the daughter cells have the genetic information to produce the enzymes and other proteins that they need

Question 3

What are the four requirements for semi - conservative replication

Answer 3

1. The four types of nucleotide, each with their bases of A, T, C, G, must be present.
2. Both strands of the DNA molecule act as a template strand for the attachment of these nucleotides
3. The enzymes DNA polymerise
4. A source of chemical energy is required to drive the process

Question 5

What is the first step of semi-conservative replication

Answer 5

The enzyme DNA helicase breaks down these nucleotides hydrogen bonds linking the base pairs of DNA

Question 6

What is the second step of semi-conservative replication

Answer 6

The double helix of the DNA strand separates into its two strands and separates

Question 7

What is the third step of DNA replication?

Answer 7

Each exposed polynucleotide stride then acts as a template to which complimentary free nucleotides bind by specific base pairing

Question 8

What is the fourth step of semi-conservative replication?

Answer 8

Nucleotides are joined together in a condensation reaction by the enzyme DNA polymerise to from the ‘missing’ polynucleotide strand on each of the two original polynucleotide strands of DNA

Question 9

What is the fifth step of semi-conservative replication

Answer 9

Each of the new DNA molecules contains one of the original DNA strands, that it, half the original DNA has been saved and built into each of the new DNA molecules