Unit one - DNA replication

Question 1

what does DNA replication need?

Answer 1

DNA polymerase and primers

Question 2

what role do primers have in DNA replication?

Answer 2

there are needed for the replication to start, their short strands of nucleotides that bind to the 3’ end of the template strand, allows the DNA polymerase to add DNA nucleotides

Question 3

what does DNA polymerase do?

Answer 3

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

Question 4

what is the result of DNA polymerase only being able to add nucleotides in one direction?

Answer 4

the leading strand being replicated continuously and the lagging strand being replicated in fragments.

Question 5

what are fragments of DNA joined together by?

Answer 5

DNA ligase

Question 6

what does the polymerase chain reaction do?

Answer 6

amplifies DNA using complementary primers for specific target sequences.

Question 7

what do primers do in PCR?

Answer 7

they are short strands of nucleotides that are complementary to specific target sequences at the two ends of the region of DNA to be amplified.

Question 8

What is the first stage of PCR?

Answer 8

DNA is heated to between 92 and 98 degrees to separate the strands

Question 9

what is the second stage of PCR?

Answer 9

DNA is cooled to between 50 and 65 degrees to allow the primers to bind to the target sequences

Question 10

what is the third stage of PCR?

Answer 10

DNA is heated to between 70 and 80 degrees for the heat-tolerant polymerase to replicate the region

Question 11

why do they use heat-tolerant DNA polymerase?

Answer 11

so it doesn’t denature when heated

Question 12

what can PCR be used for?

Answer 12

help solve crimes, settle paternity suits, diagnose genetic disorders