JMU BIO 140 Exam 2| 335 Questions
with 100% Correct Answers
What occurs to the two strands of the parental duplex during replication? Correct
Answer: they separate
Is replication conservative, semi-conservative, or dispersive? Correct Answer:
semi-conservative
What does it mean to be conservative? Correct Answer: the original DNA is kept
and an exact replica is made
What does it mean for DNA is be dispersive? Correct Answer: parts of the old and
new DNA are chopped together
What does it mean for DNA to be semi-conservative? Correct Answer: each new
daughter DNA is one old strand and one new strand
What was the experiment that proved semi-conservative? Correct Answer:
Meselsohn and Stahl experiment
What was the Meselsohn and Stahl experiment? Correct Answer: -DNA was
labeled with N15 to create heavy DNA
-After one round of replication the parent strand still contained heavy DNA but
the daughter strand contains light nitrogen
- After two rounds, half of the DNA had heavy strand and a lighter strand and the
other half had both lighter strands
What new technology confirmed the Meselsohn and Stahl experiment? Correct
Answer: fluorescent nucleotides
What energy is used to add nucleotides to a daughter strand? Correct Answer:
the breaking of the phosphate bonds from the nucleotide
,Nucleotides are added to what end of the daughter strand? Correct Answer: 3'
end
The template strand goes from what end to what end? Correct Answer: 3' to 5'
The daughter strand goes from what end to what end? Correct Answer: 5' to 3'
Where does new DNA synthesis occur? Correct Answer: replication forks
How many replication forks are there in a replication bubble? Correct Answer:
two
The lagging strand is away or towards the fork? Correct Answer: away
The leading strand is away or towards the fork? Correct Answer: towards
How many DNA polymerase are used in a replication bubble? Correct Answer: 4
Replication forks are ________. Correct Answer: asymmetrical
Define okazaki fragments Correct Answer: The noncontinuous segments of newly
synthesized DNA along the lagging strand
What are the steps of replication? Correct Answer: -unwinding of the DNA duplex
-elongation occurs from 5' to 3' on the template strand
-DNA polymerase extends the RNA primer
-A different DNA polymerase removes the primer and replaced with DNA
-fragments of the discontinuous strand are ligated with DNA ligase
What does RNA primase do? Correct Answer: lays down an RNA primer
How many RNA primers are on the leading strand? Correct Answer: one
How many RNA primers are on the lagging strand? Correct Answer: multiple
What does DNA polumerase do? Correct Answer: extends the RNA primer
, What does helicase do? Correct Answer: unwinds the DNA duplex
What does topoisomerase II do? Correct Answer: relieves the stress of the
unwinding DNA
What does single-stranded binding proteins do? Correct Answer: stabilize single
strands of DNA
What occurs when the okazaki fragments are being synthesized? Correct Answer:
the lagging strand forms a loop that persists until the new lagging strand
encounters the previous fragment
What helps the DNA when an nucleotide is added incorrectly? Correct Answer:
the proofreading function of DNA polymerase removes the incorrect nucleotide
What is the main difference in replication between eukaryotic chromosomes and
prokaryotic chromosomes? Correct Answer: eukaryotic chromosomes have
multiple origins of replication and prokaryotic chromosomes have one
How does replication start in circular chromosomes? Correct Answer: starts at
the origin and moves around the circular chromosome in both directions
What type of organism has circular chromosome? Correct Answer: bacteria
What occurs every time DNA is replicated? Correct Answer: the strand gets
slightly shorter
What helps keep DNA from shortening in every replication? Correct Answer:
telomeres and teomerase
What are the steps of telomeres and telomerase that help with replicating
chromosomal ends? Correct Answer: -terminal part of the telomere in the
template DNA strand remains unreplicated
-telomerase enzyme contains an RNA template that allows the shortened 3' end
of the template strand to be restored by the addition of more telomere repeats
with 100% Correct Answers
What occurs to the two strands of the parental duplex during replication? Correct
Answer: they separate
Is replication conservative, semi-conservative, or dispersive? Correct Answer:
semi-conservative
What does it mean to be conservative? Correct Answer: the original DNA is kept
and an exact replica is made
What does it mean for DNA is be dispersive? Correct Answer: parts of the old and
new DNA are chopped together
What does it mean for DNA to be semi-conservative? Correct Answer: each new
daughter DNA is one old strand and one new strand
What was the experiment that proved semi-conservative? Correct Answer:
Meselsohn and Stahl experiment
What was the Meselsohn and Stahl experiment? Correct Answer: -DNA was
labeled with N15 to create heavy DNA
-After one round of replication the parent strand still contained heavy DNA but
the daughter strand contains light nitrogen
- After two rounds, half of the DNA had heavy strand and a lighter strand and the
other half had both lighter strands
What new technology confirmed the Meselsohn and Stahl experiment? Correct
Answer: fluorescent nucleotides
What energy is used to add nucleotides to a daughter strand? Correct Answer:
the breaking of the phosphate bonds from the nucleotide
,Nucleotides are added to what end of the daughter strand? Correct Answer: 3'
end
The template strand goes from what end to what end? Correct Answer: 3' to 5'
The daughter strand goes from what end to what end? Correct Answer: 5' to 3'
Where does new DNA synthesis occur? Correct Answer: replication forks
How many replication forks are there in a replication bubble? Correct Answer:
two
The lagging strand is away or towards the fork? Correct Answer: away
The leading strand is away or towards the fork? Correct Answer: towards
How many DNA polymerase are used in a replication bubble? Correct Answer: 4
Replication forks are ________. Correct Answer: asymmetrical
Define okazaki fragments Correct Answer: The noncontinuous segments of newly
synthesized DNA along the lagging strand
What are the steps of replication? Correct Answer: -unwinding of the DNA duplex
-elongation occurs from 5' to 3' on the template strand
-DNA polymerase extends the RNA primer
-A different DNA polymerase removes the primer and replaced with DNA
-fragments of the discontinuous strand are ligated with DNA ligase
What does RNA primase do? Correct Answer: lays down an RNA primer
How many RNA primers are on the leading strand? Correct Answer: one
How many RNA primers are on the lagging strand? Correct Answer: multiple
What does DNA polumerase do? Correct Answer: extends the RNA primer
, What does helicase do? Correct Answer: unwinds the DNA duplex
What does topoisomerase II do? Correct Answer: relieves the stress of the
unwinding DNA
What does single-stranded binding proteins do? Correct Answer: stabilize single
strands of DNA
What occurs when the okazaki fragments are being synthesized? Correct Answer:
the lagging strand forms a loop that persists until the new lagging strand
encounters the previous fragment
What helps the DNA when an nucleotide is added incorrectly? Correct Answer:
the proofreading function of DNA polymerase removes the incorrect nucleotide
What is the main difference in replication between eukaryotic chromosomes and
prokaryotic chromosomes? Correct Answer: eukaryotic chromosomes have
multiple origins of replication and prokaryotic chromosomes have one
How does replication start in circular chromosomes? Correct Answer: starts at
the origin and moves around the circular chromosome in both directions
What type of organism has circular chromosome? Correct Answer: bacteria
What occurs every time DNA is replicated? Correct Answer: the strand gets
slightly shorter
What helps keep DNA from shortening in every replication? Correct Answer:
telomeres and teomerase
What are the steps of telomeres and telomerase that help with replicating
chromosomal ends? Correct Answer: -terminal part of the telomere in the
template DNA strand remains unreplicated
-telomerase enzyme contains an RNA template that allows the shortened 3' end
of the template strand to be restored by the addition of more telomere repeats
