11.2 DNA Replication

Question 1

Replication Fork

Answer 1

The site where the parental DNA strands separate as the DNA duplex unwinds.

Question 2

DNA replicates…

Answer 2

Semiconservatively

Question 3

Where does DNA replication begin?

Answer 3

At the replication fork

Question 4

Helicase function

Answer 4

Enzyme; separates parent strands by breaking hydrogen bonds

Question 5

Single-strand binding protein function

Answer 5

Binds to single-stranded regions to prevent rebonding

Question 6

Topoisomerase function

Answer 6

Works upstream to relieve stress from unwinding

Question 7

DNA polymerase rules

Answer 7

1. can only attach a nucleotide to another nucleotide (aka cannot lay down first nucleotide, can only elongate)
2. only adds nucleotides to the 3’ end (hydroxyl group) of another nucleotide

Question 8

What enzyme creates the primer?

Answer 8

RNA primase

Question 9

Leading strand

Answer 9

The daughter strand that is continuously synthesized

Question 10

Lagging strand

Answer 10

The daughter strand that is synthesized in short pieces. Grows away from replication fork

Question 11

Okazaki fragments

Answer 11

Short pieces laid down in the lagging strand

Question 12

DNA ligase function

Answer 12

Forms a bond between two DNA fragments

Question 13

DNA polymerase is…

Answer 13

self-correcting because of its proof-reading function

Question 14

Mutations result from

Answer 14

errors in DNA polymerase proofreading.

Question 15

What are the ultimate source of genetic variation?

Answer 15

Mutations