Question 1

Based on Griffith's results, what would you expect if you injected both heat- killed type RII and living type SIII?

Accepted Answer

The mouse lives.

Question 2

Which enzyme, a combination of several proteins and a molecule of RNA, acts as the template for the telomere repeat DNA sequence?

Accepted Answer

telomerase

Question 3

In the Hershey- Chase experiment, bacteriophages were produced in either 32P- containing or 35S- containing medium. Where were these isotopes eventually detected when the radioactively- labeled bacteriophages were introduced to a fresh bacterial culture?

Accepted Answer

A)   The 32P was associated with the culture medium and 35S was associated with the phage particles.
B)   Both 32P and 35S were associated with the bacterial cells.
C)   The 32P was associated with the culture medium and 35S was associated with the bacterial cells.
D)   Both 32P and 35S were associated with the phage particles.
E)   The 32P was associated with the bacterial cells and 35S was associated with the phage particles. E

Question 4

What is required for DNA polymerase to initiate DNA strand synthesis?

Accepted Answer

A)   a short DNA primer synthesized by the enzyme primase
B)   a short RNA primer synthesized by the enzyme primase
C)   ATP and a short RNA primer synthesized by the enzyme topoisomerase
D)   ATP and a short DNA primer synthesized by the enzyme topoisomerase
E)   DNA polymerase initiates DNA strand synthesis without requiring any additional enzymes.

Question 5

Why are telomeres problematic for eukaryotic chromosome replication?

Accepted Answer

A)   Telomerase is more error- prone than the normal DNA Polymerase.
B)   Removal of the lagging strand primer leaves a gap in the one of the strand's DNA sequences.
C)   The T loop blocks formation of primers on the lagging strand.
D)   They are highly repetitive and thus hard to replicate correctly.
E)   Maintaining very long telomeres promotes cancer cell formation.

Question 6

What type of bond is formed between the hydroxyl group of one nucleotide and the phosphate group of an adjacent nucleotide, forming the sugar- phosphate backbone of DNA?

Accepted Answer

A)   phosphodiester bond
B)   glycosidic bond
C)   hydrogen bond
D)   ester linkage
E)   ionic bond

Question 7

Why do origins of replication in various bacteria have conserved DNA consensus sequences?

Accepted Answer

A)   Fewer mutations in the DNA occur at the very beginning of replication at the origin, hence why they are conserved as consensus sequences.
B)   It is more efficient to use the same sequence multiple times in different genomes than to change it.
C)   The consensus sequence allows the origin to wrap into a circle and recruit replication initiation proteins.
D)   Origins need to be recognized by replication initiation proteins to open up their AT- rich regions.
E)   Consensus sequences are found throughout bacterial genomes and so would be found at the origin as well.

Question 8

What is the difference between a nucleotide and a nucleoside?

Accepted Answer

A)   Nucleotides are involved in eukaryotic DNA replication, while nucleosides are used in bacterial DNA replication.
B)   A nucleoside with a phosphate ester linked to the sugar is a nucleotide.
C)   Nucleosides contain only deoxyribose sugars.
D)   Nucleosides are purines, while nucleotides are pyrimidines.
E)   Nucleotides are found in DNA, while nucleosides are found in RNA.

Question 9

The following represents a DNA strand in the process of replication. The bottom sequence is that of DNA strand with polarity indicated and the top sequence represents the RNA primer. 
GGGGCCUUU
5' AAATCCCCGGAAACTAAAC 3'
Which of the following will be the first DNA nucleotide added to the primer?

Accepted Answer

A)   T
B)   U
C)   C
D)   G
E)   A

Question 10

Comparison of conserved sequences among related species usually leads to the identification of ______, which illustrate the nucleotides most often found at each position of DNA in the conserved region.

Accepted Answer

The answer of Comparison of conserved sequences among related species...

Question 11

The extraordinary accuracy of the DNA polymerase III enzyme lies in its ability to "proofread" newly synthesized DNA, a function of the enzyme's__________ .

Accepted Answer

A)   3'- to- 5' helicase activity
B)   5'- to- 3' polymerase activity
C)   3'- to- 5' exonuclease activity
D)   5'- to- 3' exonuclease activity
E)   3'- to- 5' polymerase activity

Question 12

What is removed from dNTPs to provide the energy required for DNA polymerase to catalyze DNA strand elongation?

Accepted Answer

The answer of What is removed from dNTPs to provide...

Question 13

What proteins bind the DNA sequences found at the origins of replication?

Accepted Answer

The answer of What proteins bind the DNA sequences found...

Question 14

Based on the following replication bubble, which of these statements is true?

Accepted Answer

A)   W and Z are leading strands, X and Y are lagging strands
B)   X and Z are leading strands, W and Y are lagging strands
C)   X and Y are leading strands, W and Z are lagging strands
D)   W and Y are leading strands, X and Z are lagging strands
E)   X and W are leading strands, Y and Z are lagging strands

Question 15

What is the overall direction of DNA strand elongation?

Accepted Answer

The answer of What is the overall direction of DNA...

Question 16

Avery, Macleod, and McCarty expanded on Griffith's experiment to prove that DNA is the hereditary molecule required for transformation. What treatment of the heat- killed SIII bacteria extract resulted in the mouse LIVING?

Accepted Answer

A)   Destruction of type SIII DNA with DNase
B)   Destruction of type SIII lipids and polysaccharides
C)   Destruction of type SIII RNA with RNase
D)   Destruction of type SIII proteins with protease
E)   Use of the control group (null treatment) , in which all components are intact

Question 17

What structure in E. coli delivers primase and accessory proteins to the oriC site to synthesize the primer needed for DNA replication?

Accepted Answer

The answer of What structure in E. coli delivers primase...

Question 18

What is the purpose of the 3'- to- 5' exonuclease activity of DNA Polymerase?

Accepted Answer

A)   Removing mismatched nucleotides at the polymerase active site increases the rate of synthesis in the 5' to 3' direction.
B)   Degrade excessive nucleotides on Okazaki fragments.
C)   Remove mismatched nucleotides in the template strand.
D)   Some polymerases do not have exonuclease activity.
E)   Remove mismatched nucleotides in the newly synthesized strand.

Question 19

During DNA replication in E. coli, how does the cell prevent the DNA strands from following their natural tendency to seek maximum stability and reanneal?

Accepted Answer

The answer of During DNA replication in E. coli, how...

Question 20

DNA polymerase requires a primer sequence to provide a________ functional group to which the new DNA nucleotide can be added.

Accepted Answer

The answer of DNA polymerase requires a primer sequence to...

Exam 7: Dna Structure and Replication