Log in
Biology
1
answer
0
watching
95
views

DNA polymerase I of E. coli has the three activities listed below. Enter the letter that describes each activity. (There is only one letter per activity)

3’à 5’ exonuclease___ 5’à 3’ polymerase___ 5’à 3’ exonuclease___

a.Recognizes the origin of replication

b. Removes the primers from the new DNA strand

c. Seals nicks in the sugar phosphate backbone of the new DNA strand

d. Adds dNTPs to the growing DNA strand

e. Removes mismatched bases from the new DNA strand

f. Recognizes specific termination sequences in the template strand

Watch
1
answer
0
watching
95
views

For unlimited access to Homework Help, a Homework+ subscription is required.

Collen Von
Collen VonLv2
28 Sep 2019

Unlock all answers

Get 1 free homework help answer.
Already have an account? Log in
Share

Related textbook solutions

Molecular Cell Biology
8 Edition,
Lodish
ISBN: 9781464183393
Biology: Science for Life with Physiology
6 Edition,
Belk
ISBN: 9780134555430
Biology
2nd Edition, 2013
Openstax
ISBN: 9781947172517
Concepts of Biology
OER Edition,
Openstax
ISBN: 9781938168116
Essentials of Biology
5 Edition,
Mader
ISBN: 9781259660269

Related questions

Please help to check if the following DNA repair description is correct. if not, please help to correct. thanks!!

1. Base Excision Repair

DNA plycosylase comes in and removes deaminated C Uracil. AP endonuclease recognizes the missing tooth created by DNA glysosylase and it removes the sugar while phosphodiesterase removes phosphate group leaving DNA helix with single nucleotide gap. DNA polymerase add new nucleotide and DNA ligase seals the nick

2. Nucleotide Excision Repair

NER uses to remove large mutation. Excision nuclease comes in and cut the pyrimidine primers in a big chunk. DNA helicase removes the big chunk. DNA polymeraze synthesize nucleotides and DNA ligase seals the nick.

3. Nonhomologous end joining

The overhangs ends is recognized by Ku heterodimers and they attach to the broken chromosomes end. Additional proteins attach and join covalently. Overhangs are then digested and ligase seals the nicks

4. The repair involves sister chromatids. One of the sister chromatids has double strand breaks. Exonuclease activity degrades the 5’ end. The strand invasion begins by crossing over. The single strand interacts with healthy strand on sister chromatid DNA molecule. DNA polymerase synthesize missing nucleotides and ligase seals the nicks

Which of the following are required for DNA replication by DNA polymerase?

A. Template strand
B. Short, complementary primer strand
C. 5'-dXTPs
D. 3'-dXTPs
E. Answers (A) and (C)
F. Answers (A) and (D)
G. Answers (A), (B), and (C)

H. Answers (A), (B), and (D)

Which of the following are reasons why DNA replication must be discontinuous?

A. The complementary strands have opposite polarity
B. Only 5'-dXTPs are available in cells
C. DNA polymerase only adds 5-'dXTPs to 3'-OH ends
D. All the above
E. Answers (A) and (C)
F. Answers (B) and (C)

G. Answers (A) and (B)

Which of the following are roles of RNA polymerases in DNA replication?

A. RNA polymerase (primase) initiates replication at the origin
B. RNA polymerase synthesizes the primers for Okazaki fragments
C. Both (A) and (B)

D. Neither (A), nor (B)

Which of the following statements describes the activity of DNA polymerase?

A. DNA polymerase adds 3’-dXTPs to the 5’-OH terminus of the primer
B. DNA polymerase adds 5'-dXTPs to the 3’-OH terminus of the primer
C. DNA polymerase adds 5’-dXTPs to the 3’-phosphate terminus of the primer
D. DNA polymerase adds 3’-dXTPs to the 5’-phosphate terminus of the primer

1. In addition to identifying the genetic material, the experiments of Avery, MacLeod, and McCarty with different strains of Streptococcus pneumoniae demonstrated that
DNA is a double helix.
DNA may be taken up by bacterial cells and be active.
DNA is present in bacteriophage T2.
eukaryotic cells may be genetically transformed.
DNA binds to the cell wall of the bacterium.
2. In order to show that DNA in cell extracts is responsible for genetic transformation in Streptococcus pneumoniae, important corroborating evidence should indicate that _______ also destroy transforming activity.
temperatures high enough to kill cells
enzymes that hydrolyze proteins
enzymes that hydrolyze DNA
enzymes that hydrolyze polysaccharides
enzymes that hydrolyze RNA
3. Based on what you have learned about the experiments conducted by Griffith and Avery and colleagues with bacteria, which of the following would result in transformation of living R cells?
Pure RNA from S cells
Cell-membrane extracts from S cells
A mixture of pure RNA and protein from S cells
Cell-free extracts from S cells
Pure protein from S cells
4. A-T base pairs in a DNA double helix
form three hydrogen bonds with each other.
are more heat-stable than G-C base pairs.
are of a substantially different length than G-C base pairs.
are not accessible to DNA binding proteins.
are chemically distinct from G-C base pairs.
5. If 23 percent of the bases in a sample of double-stranded DNA are adenine, what percentage of the bases are uracil?
27
50
0
73
23
6. The uniform diameter of the DNA structure provides evidence for
antiparallel DNA strands.
a right-handed helix.
a double-stranded helix.
3′ end phosphorylation.
purine–pyrimidine pairing.
7. If a sequence of one strand of DNA is 5′-TGACTATC-3′, what is the complementary strand?
5′-ACTGATAG-3′
3′-TGACTATC-5′
3′-ACTGATAG-5′
3′-ACTGATAG-3′
5′-TGACTATC-3′
8. What structural aspect of the DNA facilitates dissociation of the two DNA strands for replication?
3′ end phosphorylation
Purine–pyrimidine pairing
Antiparallel DNA strands
Covalent bonds between sugars and phosphate groups
Hydrogen bonding between paired bases
9. If the Meselson–Stahl density gradient experiment had resulted in two bands of DNA molecules after only one round of replication, one containing only 15N and the second only 14N, this result would have indicated that replication was
unidirectional.
dispersive.
conservative.
bidirectional.

semiconservative.
10. The nucleoside analogue acyclovir, which is used to treat herpes simplex virus (HSV) infections, lacks a 3′ hydroxyl group (–OH). Predict what will happen if the host cell DNA polymerase incorporates a molecule of acyclovir into an elongating strand of HSV DNA.
The replication complex will no longer bind to origins of replication.
The DNA polymerase will only incorporate acyclovir molecules.
Acyclovir will bind single-strand binding proteins.
DNA polymerase will not be able to link a successive nucleotide.
Acyclovir will block the activity of the DNA helicase.
11. Which of the following does not demonstrate the stability of the DNA double helix?
Single-strand binding proteins are required to keep the strands apart.
Paired bases form hydrogen bonds.
High temperatures are required to denature it.
DNA synthesis requires energy.
DNA helicases require ATP.
12. What effect would a primase inhibitor have on DNA replication?
DNA polymerase would not be able to add bases to the DNA.
Primase would be blocked from joining the DNA replication complex.
Primase would not be able to provide primers for DNA polymerases.
DNA polymerase would not be able to use DNA as a template.
There would be no effect on DNA replication.
13. To replicate their DNA in a timely manner, most eukaryotic chromosomes
normally have uncoiled DNA.
have multiple origins of replication.
contain linear molecules of single-stranded DNA.
have two replication forks that move in the same direction.
are composed entirely of DNA.
14. Which statement about DNA replication is false?
Okazaki fragments are synthesized as parts of the leading strand.
Error rates for DNA replication are reduced by proofreading of the DNA polymerase.
The sliding clamp increases the rate of DNA synthesis.
Replication forks represent areas of active DNA synthesis on the chromosomes.
Ligases and polymerases function in the vicinity of replication forks.
15. In many eukaryotes, there are repetitive sequences called telomeres at the ends of chromosomes. After successive rounds of DNA replication, the _______ strand becomes shorter. In some cells, an enzyme called _______ repairs the shortened strand.
leading; telomerase
lagging; telomerase
lagging; DNA polymerase I
leading; DNA polymerase I
leading; replicase
16. A researcher studies normal human fibroblast cells. They can be maintained in culture but die off after about 30 cell generations. Unexpectedly, a colony of cells continues to survive and divide past 30 generations. Which scenario is most likely true for these cells?
DNA polymerase is constantly active.
Primase is able to extend the telomeres.
The mismatch repair system is extra efficient.
The telomerase gene is being expressed.
The cells do not need the ends of their chromosomes.
17. If DNA polymerase III introduces an incorrect nucleotide, what is the first corrective action made by the DNA repair system?
The replication complex excises the incorrect nucleotide.
The excision repair proteins remove the incorrect nucleotide.
The mismatch repair system scans for base-pairing mismatches.
There is no correction, because nucleotide errors by DNA polymerases are not repaired.
DNA ligase connects the correct nucleotide.
18. Choose the correct order of the following four events in the excision repair of DNA:
(1) Base-paired DNA is made complementary to the template.
(2) Damaged bases are recognized.
(3) DNA ligase seals the new strand to existing DNA.
(4) Part of a single strand is excised.
1, 2, 3, 4
2, 1, 3, 4
3, 4, 2, 1
2, 4, 1, 3
4, 2, 3, 1
19. Six complete cycles of PCR should result in a _______-fold increase in the amount of DNA.
64
32
12
128
6
20. When double-stranded DNA is heated to temperatures above 90°C, it denatures. Denaturation is a process that
breaks covalent bonds.
hydrolyzes DNA.
separates double-stranded DNA into two single strands.
causes new hydrogen bonds to form.
irreversibly destroys the double helical structure.

Weekly leaderboard

Home
Homework Help 3,900,000
Biology 460,000
Start filling in the gaps now
Log in