Replication of DNA - learning outcomes/ questions

Question 1

Prior to cell division, DNA is replicated by what?

Answer 1

Prior to cell division, DNA is replicated by a DNA polymerase.

Question 2

DNA polymerase needs what to start replication?

Answer 2

DNA polymerase needs primers to start replication.

Question 3

A primer is a what and what does it allow?

Answer 3

A primer is a short strand of nucleotides which binds to the 3’ end of the template DNA strand allowing polymerase to add DNA nucleotides.

Question 4

DNA what adds DNA nucleotides, using what base pairing, to the deoxyribose (3’) end of the new DNA strand which is forming?

Answer 4

DNA polymerase adds DNA nucleotides, using complementary base pairing, to the deoxyribose (3’) end of the new DNA strand which is forming.

Question 5

What happens to the DNA during/ after DNA polymerase adds DNA nucleotides, using complementary base pairing, to the deoxyribose (3’) end of the new DNA strand which is forming?

Answer 5

DNA is unwound and hydrogen bonds between bases are broken to form two template strands.

Question 6

DNA what can only add DNA nucleotides what direction resulting in the leading strand being replicated continuously and the lagging strand replicated in fragments?

Answer 6

DNA polymerase can only add DNA nucleotides in one direction resulting in the leading strand being replicated continuously and the lagging strand replicated in fragments.

Question 7

Fragments of DNA are joined together by what?

Answer 7

Fragments of DNA are joined together by ligase.

Question 8

(PCR) amplifies what using complementary primers for specific target sequences.

Answer 8

(PCR) amplifies DNA using complementary primers for specific target sequences.

Question 9

In PCR, primers what?

Answer 9

In PCR, primers are short strands of nucleotides which are complementary to specific target sequences at the two ends of the region of DNA to be amplified.

Question 10

DNA is heated to between what to separate the strands?

Answer 10

DNA is heated to between 92 and 98 °C to separate the strands.

Question 11

What happens to allow primers to bind to target sequences?

Answer 11

It is then cooled to between 50 and 65 °C to allow primers to bind to target sequences.

Question 12

It is then heated to between what for heat-tolerant DNA polymerase to replicate what?

Answer 12

It is then heated to between 70 and 80 °C for heat-tolerant DNA polymerase to replicate the region of DNA.

Question 13

Why is PCR good?

Answer 13

PCR can amplify DNA to help solve crimes, settle paternity suits and diagnose genetic disorders.