U1: 2- Structure And Replication Of DNA

Question 1

To which carbon attachment points do bases and phosphates attach in a DNA nucleotide?

Answer 1

Carbon 1 and carbon 5

Question 2

What name is given to the backbone of a DNA strand formed from deoxyribose sugar and phosphate?

Answer 2

Sugar-phosphate backbone

Question 3

What type of bonds form between bases on two complimentary strands?

Answer 3

Hydrogen bonds

Question 4

What term is used to describe the fact that the two strands of DNA run in opposite directions to each other?

Answer 4

Antiparallel

Question 5

Name the two ends of one DNA strand?

Answer 5

3’ and 5’ ends

Question 6

What name is given to the arrangement of the two strands of DNA?

Answer 6

Double helix

Question 7

What name is given to the strand that is found on the left hand side on a DNA strand that runs from 3’ to 5’?

Answer 7

Leading strand

Question 8

What name is given to the short sequence of nucleotides that attach to the 3’ end of the parental strand about to be replicated?

Answer 8

Primer

Question 9

What name is given to the enzyme needed to replicate the strands during DNA replication?

Answer 9

DNA polymerase

Question 10

How is the replication of the leading strand described because it is replicated without any interruptions?

Answer 10

Continuous

Question 11

What name is given to the strand opposite the leading strand?

Answer 11

Lagging strand

Question 12

How is replication of the lagging strand described because it is replicated in fragments?

Answer 12

Discontinuous

Question 13

Name the enzyme needed to join the fragments together in the lagging strand

Answer 13

Ligase

Question 14

Name 5 requirements of DNA replication

Answer 14

• DNA template strand
• ATP
• DNA nucleotides
• primers
• enzymes (DNA polymerase and ligase)

Question 15

What name is given to the technique that can be used to create many copies of a piece of DNA outside of the body?

Answer 15

Polymerase chain reaction (PCR)

Question 16

What word is used to describe the fact that you are making multiple copies of a piece of DNA in a PCR?

Answer 16

Amplification

Question 17

Describe the first stage of PCR

Answer 17

Heat the DNA strand to 92-98°C to break the hydrogen bonds and separate the strands

Question 18

The next stage of PCR after heating involves cooling the DNA down to between 50-65°C. Why does the DNA have to be cooled?

Answer 18

So that primers can attach

Question 19

Lastly the DNA is heated to 70-80°C to allow an enzyme to replicate the strand. Name the enzyme involved.

Answer 19

Heat-tolerant DNA polymerase

Question 20

Name three uses of amplified DNA produced through PCR

Answer 20

• forensic (crime scene investigation)
• medical (genetic disorder diagnosis)
• paternity disputes