Ch 13-2

Question 1

What were the two rival theories for replication until the late 1950s?

Answer 1

Conservative and dispersive replication

Question 2

Whose experiment proved the semi-conservative form of replication?

Answer 2

Matthew Meselson and Franklin Stahl

Question 3

What is the name for the sites where DNA replication begins?

Answer 3

Origins of replication

Question 4

What enzyme unwinds the DNA strands at the replication fork?

Answer 4

Helicase

Question 5

What is the function of single-strand binding proteins

Answer 5

To keep the single strands of DNA from rebinding to one another

Question 6

What enzyme creates a short RNA primer to initiate DNA synthesis?

Answer 6

Primase

Question 7

In what direction is DNA synthesized?

Answer 7

5’ – 3’ direction

Question 8

On which strand of DNA does synthesis occur continuously?

Answer 8

Leading strand

Question 9

What are the short fragments of DNA synthesized on the lagging strand called?

Answer 9

Okazaki fragments

Question 10

What enzyme joins together the Okazaki fragments?

Answer 10

DNA ligase

Question 11

Meselson and Stahl grew E.coli in media with nucleotide precursors using ________ (heavier)

Answer 11

15 N

Question 12

If conservative replication was correct, DNA of _________ densities would have been found after the first replication

Answer 12

Two

Question 13

Eukaryotic cells can have ________ of origins of replication

Answer 13

Thousand

Question 14

__________ enzymes help to relieve strain ahead of the replication fork.

Answer 14

Topoisomerase

Question 15

The enzymes which synthesize DNA are not able to __________ the synthesis reaction

Answer 15

Initiate

Question 16

DNA nucleotides are indicated as ___________ to indicate the presence of deoxyribose rather than ribose.

Answer 16

dNTP

Question 17

The two strands of DNA run ___________ to one another

Answer 17

Antiparallel

Question 18

Synthesis on the lagging strand cannot occur ___________.

Answer 18

Continuously

Question 19

Okazaki fragments are 100-200 dNTP long in ___________.

Answer 19

Eukaryotes

Question 20

What type of macromolecule did most scientists originally believe was the inherited material?
○
A. Lipids
○
B. Proteins
○
C. Carbohydrates
○
D. Nucleic Acids

Answer 20

B

Question 21

Bacterial transformation involves what type of genetic transfer?
○
A. Horizontal
○
B. Vertical
○
C. Diagonal
○
D. None of the above

Answer 21

A

Question 22

Who determined that even proportions of matching bases were found across numerous species?
○
A. Rosalind Franklin
○
B. James Watson
○
C. Francis Crick
○
D. Erwin Chargaff

Answer 22

D

Question 23

What technique did Rosalind Franklin use to capture the first images of DNA?
○
A. Microscopy
○
B. Chromatography
○
C. X-ray diffraction
○
D. Electrophoresis

Answer 23

C

Question 24

What form of chromatin is easily accessibly and available for transcription?
○
A. Heterochromatin
○
B. Euchromatin
○
C. Chromatin
○
D. None of the above

Answer 24

B

Question 25

The Meselson-Stahl experiment proved which model of replication? ○ A. Conservative ○ B. Semiconservative ○ C. Dispersive ○ D. None of the above

Answer 25

B

Question 26

How many origins of replication do prokaryotes have? ○ A. One ○ B. Two ○ C. Thousands ○ D. It varies depending on the species

Answer 26

A

Question 27

What is the function of DNA polymerase? ○ A. To unwind the DNA double helix ○ B. To create a short RNA primer ○ C. To synthesize new DNA strands ○ D. To join together Okazaki fragments

Answer 27

C

Question 28

In which direction does DNA polymerase add nucleotides to the growing DNA strand? ○ A. 3’ to 5’ ○ B. 5’ to 3’ ○ C. Both directions ○ D. It varies depending on the strand

Answer 28

B

Question 29

What is the function of DNA ligase? ○ A. To unwind the DNA double helix ○ B. To create a short RNA primer ○ C. To synthesize new DNA strands ○ D. To join together Okazaki fragments

Answer 29

D

Question 30

T/f DNA replication is a conservative process.

Answer 30

F DNA replication is a semi-conservative process.

Question 31

T/ f Meselson and Stahl used isotopes of nitrogen to distinguish between old and new DNA strands.

Answer 31

T

Question 32

T/f Prokaryotes have multiple origins of replication.

Answer 32

F Prokaryotes have a single origin of replication.

Question 33

T/f Helicase unwinds the DNA double helix at the replication fork.

Answer 33

T

Question 34

T/f Topoisomerase prevents the DNA strands from rebinding.

Answer 34

F Single-strand binding proteins prevent the DNA strands from rebinding.

Question 35

T/f Primase synthesizes a short RNA primer to provide a starting point for DNA polymerase

Answer 35

T

Question 36

T/f DNA polymerase can initiate the synthesis of a new DNA strand without a primer.

Answer 36

F DNA polymerase cannot initiate the synthesis of a new DNA strand without a primer.

Question 37

T/f The leading strand is synthesized continuously, while the lagging strand is synthesized discontinuously.

Answer 37

T

Question 38

T/f Okazaki fragments are found on the leading strand.

Answer 38

Okazaki fragments are found on the lagging strand.

Question 39

T/f DNA ligase seals the gaps between Okazaki fragments.

Answer 39

T