WorksheetsUNIT 6- Ch 16 quiz
Total questions: 21
Worksheet time: 21mins
Who conducted the X-ray diffraction studies that were key to the discovery of the structure of DNA?
a)Griffith
b)Franklin
c)Meselson and Stahl
d)Chargaff
e)McClintock
What enzyme compensates for replication-associated shortening of linear chromosomes?
a)DNA polymerase II
b)ligase
c)telomerase
d)DNA nuclease
e)proofreading enzyme
How do the leading and the lagging strands differ?
a)The leading strand is synthesized in the same
direction as the movement of the replication fork,
whereas the lagging strand is synthesized in the
opposite direction.
b)The leading strand is synthesized at twice the rate of the lagging strand.
c)The lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together.
d)The leading strand is synthesized by adding nucleotides to the 3′ end of the growing strand, whereas the lagging strand is synthesized by adding nucleotides to the 5′ end.
Which of the following is true of heterochromatin but not of euchromatin?
a)It is accessible to enzymes needed for gene expression.
b)It becomes less tightly compacted after cell division.
c)It includes DNA primarily found in expressed genes.
d)It appears more pale when observed microscopically.
e)It remains tightly coiled at the G1 phase.
Suppose a double-stranded DNA molecule was shown to have 22% guanine bases. What would be the expected percentage of adenine bases in that molecule?
a)22%
b)28%
c)50%
d)78%
e)not enough information
Which of the following results from Griffith’s experiment is an example of transformation?
a)Mouse dies after being injected with living S cells.
b)Mouse is healthy after being injected with living R cells.
c)Mouse is healthy after being injected with heat-killed
S cells.
d)Mouse dies after being injected with a mixture of heat-
killed S and living R cells.
e)In blood samples from the mouse in d, living S cells were found.
Nitrogenous bases are paired in specific combinations. Which of the following does not provide evidence to support this conclusion?
a)A purine-purine pair is too wide to account for the
2-nm diameter of the double helix.
b)A pyrimidine-pyrimidine pair is too narrow to account for the 2-nm diameter of the double helix.
c)The X-ray data suggested that the double helix had a uniform diameter.
d)Whenever one strand of DNA has an A, the partner strand has a T.
e)The pairs of nitrogenous bases are held together by hydrogen bonds.
In Meselson and Stahl’s experiment proving semiconservative DNA replication, they started with bacteria grown in a heavy isotope of nitrogen and then switched them to a light isotope. They then observed the DNA density after one and two rounds of replication. What was the result after one round of replication?
a)equal amounts of light and hybrid DNA
b)all hybrid DNA
c)equal amounts of light, hybrid, and heavy DNA
d)twice as much light as hybrid DNA
e)three times as much light as hybrid DNA
Suppose a 100-base-pair, double-stranded DNA molecule consists of 15% thymine bases. How many total hydrogen bonds are holding the two strands together?
a)30
b)60
c)100
d)270
e)500
In Meselson and Stahl’s experiment proving semiconservative DNA replication, they started with bacteria grown in a heavy isotope of nitrogen and then switched them to a light isotope. They then observed the DNA density after one and two rounds of replication. What was the result after two rounds of replication?
a)equal amounts of light and hybrid DNA
b)all hybrid DNA
c)equal amounts of light, hybrid, and heavy DNA
d)twice as much light as hybrid DNA
e)three times as much light as hybrid DNA.
Imagine a bacterial replication fork. Synthesis of which new strand(s) would be affected by mutations in the enzyme DNA polymerase I?
a)leading strand
b)lagging strand
c)both leading and lagging strands
d)neither leading nor lagging strand
Imagine a bacterial replication fork. Synthesis of which new strand(s) would be affected by mutations in the enzyme DNA polymerase III?
a)leading strand
b)lagging strand
c)both leading and lagging strands
d)neither leading nor lagging strand
In Meselson and Stahl’s experiment proving semiconservative DNA replication, they started with bacteria grown in a heavy isotope of nitrogen and then switched them to a light isotope. They then observed the DNA density after one and two rounds of replication. If they had measured after a third round of replication, what would they have observed?
a)equal amounts of light and hybrid DNA
b)all hybrid DNA
c)equal amounts of light, hybrid, and heavy DNA
d)twice as much light as hybrid DNA
e)three times as much light as hybrid DNA
Imagine a bacterial replication fork. Synthesis of which new strand(s) would be affected by mutations in the enzyme primase?
a)leading strand
b)lagging strand
c)both leading and lagging strands
d)neither leading nor lagging strand
Does the distribution of bases in sea urchin DNA and salmon DNA follow Chargaff’s rules?
a)Yes, because the %A + %T is greater than the %G + %C in both species.
b)No, because %A + %T does not equal %G + %C in both species.
c)Yes, because the %A approximately equals the %T and
the %G approximately equals the %C in both species.
d)No, because %A is higher than %T and %G is higher than %C in both species.
Imagine a bacterial replication fork. Synthesis of which new strand(s) would be affected by mutations in the enzyme DNA ligase?
a)leading strand
b)lagging strand
c)both leading and lagging strands
d)neither leading nor lagging strand
Which of the following phenomena or processes does not contribute to the high fidelity of DNA replication?
a)base pairing
b)telomerase
c)proofreading
d)mismatch repair
4. This repetitive sequences of DNA on the ends of chromosomes (TTAGGG) for protection.
telomeres
telomerase
Okazaki fragments
prime
Experiment that radioactively labeled the proteins and DNA of bacteriophages to determine if DNA or protein was the transforming agent
Avery
Watson & Crick
Messelson & Stahl
Hershey & Chase
What is meant by the description "antiparallel" regarding the strands that make up DNA?
The twisting nature of DNA creates nonparallel strands.
One strand is positively charged and the other is negatively charged.
The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.
Base pairings create unequal spacing between the two DNA strands
Suppose a double-stranded DNA molecule was shown to have 15% adenine bases. What would be the expected percentage of guanine bases in that molecule?
15%
35%
85%
Not enough information
