DNA Replication

Question 1

Name the mechanism of DNA replication

Answer 1

Semi-conservative

Question 2

What is the role of DNA polymerase do in DNA replication?

Answer 2

Joins adjacent nucleotides via condensation reactions

Question 3

Name the enzyme that breaks hydrogen bonds between bases on DNA strands

Answer 3

DNA helicase

Question 4

Why is DNA replication described as semi-conservative?

Answer 4

New DNA molecules consist of one old polynucleotide strand and one new polynucleotide strand

Question 5

Where are free DNA nucleotides found?

Answer 5

In the nucleus

Question 6

What does a DNA nucleotide consist of?

Answer 6

Deoxyribose sugar, phosphate and a nitrogenous base

Question 7

If the base sequence on the original polynucleotide strand is ACTGAGTTC, what will the base sequence be on the new polynucleotide strand?

Answer 7

TGACTCAAG

Question 8

Which scientists provided experimental evidence for semi-conservative DNA replication?

Answer 8

Meselsohn and Stahl

Question 9

Name the part of the DNA molecule that contains nitrogen

Answer 9

Base

Question 10

In Meselsohn and Stahl’s experiment, explain why, after one generation all the DNA is made up of an equal mixture of light (N14) and heavy (N15) nitrogen.

Answer 10

E.coli was initially cultured on heavy (N15) nitrogen and then subsequent generations were grown on light (N14) nitrogen. Old strands consist of heavy (N15) nitrogen, new strands consist of light (N14) nitrogen