Molecular and Cellular Biology - Exam 1 Test Bank 6
The process of DNA replica on requires that each of the parental DNA strands be used as a _____ to
produce a duplicate of the opposing strand - (c) template
DNA replica on is considered semiconserva ve because - (c) each daughter DNA molecule consists of
one strand from the parents DNA molecules and one new strand
(d) true, but not correct - new DNA strands must be copied from a DNA template
The classic experiments conducted by Meselson and Stahl demonstrated that DNA replica on is
accomplished by employing a mechanism - (b) semiconserva ve
Ini ator proteins bind to replica on origins and disrupt hydrogen bonds between the two DNA strands
being copied. Which of the factors below does not contribute to the rela ve ease of strand separa on by
ini ator proteins? - (b) the reac on can occur at room temperature
If the genome of the bacterium E. coli requires about 20 minutes to replicate itself, how can the genome
of the fruit fly Drosophila be relocated in only 3 minutes? - (d) Drosophila DNA contains more origins of
replica on than E. coli DNA
6-6 -
(A) When DNA is being replicated inside a cell, local hea ng occurs, allowing the two strands to separate
(B) DNA replica on origins are typically rich in G-C base pairs
(C) Meselson and Stahl ruled out the dispersive model for DNA replica on
(D) DNA replica on is a bidirec onal process that is ini ated at mul ple loca ons along chromosomes in
eukaryo c cells - (A) FALSE - the two strands do need to separate for replica on to occur but this is
accomplished by the binding of ini ator proteins at the origin of replica on
(B) FALSE - DNA replica on origins are typically rich in A-T base pairs, which are held together by only
two hydrogen bonds (instead of three for C-G base pairs), making it easier to separate the strands at
these sites
, (C) TRUE
(D) TRUE
How many replica on forks are formed when an origin of replica on is opened? - (b) 2
(A) On a DNA strand that is being synthesized, which end is growing - the 3' end, the 5' end, or both
ends?
(B) On a DNA strand that is being used as a template, where is the copying occurring rela ve to the
replica on origin - 3' of the origin, 5', or both? - (A) The 3' end - DNA polymerase can add nucleo des
only to the 3'-OH end of a nucleic acid chain
(B) Both, as a result of the bidirec onal nature of chromosomal replica on
How does the total number of replica on origins in bacterial cells compare with the number of origins in
human cells? - (d) 1 verses 10,000
Which of the following statements correctly explains what it means for DNA replica on to be
bidirec onal? - (d) the replica on forks formed at the origin move in opposite direc ons
The chroma n structure in eukaryo c cells is much more complicated than that observed in prokaryo c
cells. This is thought to be the reason that DNA replica on occurs much faster in prokaryotes. How much
faster is it? - (c) 10x
DNA polymerase catalyzes the joining of a nucleo de to a growing DNA strand. What prevents this
enzyme from catalyzing the reverse reac on? - (a) hydrolysis of pyrophosphate (PPi) to inorganic
phosphate (Pi) + Pi
6-14 -
6-15 -
6-16 -
The process of DNA replica on requires that each of the parental DNA strands be used as a _____ to
produce a duplicate of the opposing strand - (c) template
DNA replica on is considered semiconserva ve because - (c) each daughter DNA molecule consists of
one strand from the parents DNA molecules and one new strand
(d) true, but not correct - new DNA strands must be copied from a DNA template
The classic experiments conducted by Meselson and Stahl demonstrated that DNA replica on is
accomplished by employing a mechanism - (b) semiconserva ve
Ini ator proteins bind to replica on origins and disrupt hydrogen bonds between the two DNA strands
being copied. Which of the factors below does not contribute to the rela ve ease of strand separa on by
ini ator proteins? - (b) the reac on can occur at room temperature
If the genome of the bacterium E. coli requires about 20 minutes to replicate itself, how can the genome
of the fruit fly Drosophila be relocated in only 3 minutes? - (d) Drosophila DNA contains more origins of
replica on than E. coli DNA
6-6 -
(A) When DNA is being replicated inside a cell, local hea ng occurs, allowing the two strands to separate
(B) DNA replica on origins are typically rich in G-C base pairs
(C) Meselson and Stahl ruled out the dispersive model for DNA replica on
(D) DNA replica on is a bidirec onal process that is ini ated at mul ple loca ons along chromosomes in
eukaryo c cells - (A) FALSE - the two strands do need to separate for replica on to occur but this is
accomplished by the binding of ini ator proteins at the origin of replica on
(B) FALSE - DNA replica on origins are typically rich in A-T base pairs, which are held together by only
two hydrogen bonds (instead of three for C-G base pairs), making it easier to separate the strands at
these sites
, (C) TRUE
(D) TRUE
How many replica on forks are formed when an origin of replica on is opened? - (b) 2
(A) On a DNA strand that is being synthesized, which end is growing - the 3' end, the 5' end, or both
ends?
(B) On a DNA strand that is being used as a template, where is the copying occurring rela ve to the
replica on origin - 3' of the origin, 5', or both? - (A) The 3' end - DNA polymerase can add nucleo des
only to the 3'-OH end of a nucleic acid chain
(B) Both, as a result of the bidirec onal nature of chromosomal replica on
How does the total number of replica on origins in bacterial cells compare with the number of origins in
human cells? - (d) 1 verses 10,000
Which of the following statements correctly explains what it means for DNA replica on to be
bidirec onal? - (d) the replica on forks formed at the origin move in opposite direc ons
The chroma n structure in eukaryo c cells is much more complicated than that observed in prokaryo c
cells. This is thought to be the reason that DNA replica on occurs much faster in prokaryotes. How much
faster is it? - (c) 10x
DNA polymerase catalyzes the joining of a nucleo de to a growing DNA strand. What prevents this
enzyme from catalyzing the reverse reac on? - (a) hydrolysis of pyrophosphate (PPi) to inorganic
phosphate (Pi) + Pi
6-14 -
6-15 -
6-16 -
