DNA is synthesized through a process known as _____.
semiconservative replication conservative
replication translation transcription
What is meant by the description "antiparallel" regarding
the strands that make up DNA?
The twisting nature of DNA creates nonparallel strands.
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. One strand
contains only purines and the other contains only pyrimidines.
How does the enzyme telomerase meet the challenge of replicating the
ends of linear chromosomes?
It adds a single 5' cap structure that resists degradation by
nucleases. It causes specific double-strand DNA breaks that
result in blunt ends on both strands. It catalyzes the
lengthening of telomeres, compensating for the shortening that could
occur during replication without telomerase activity. It
adds numerous GC pairs, which resist hydrolysis and maintain
What is a telomere?
the mechanism that holds two sister chromatids together
DNA replication during telophase the site of origin of
DNA replication the ends of linear chromosomes
The leading and the lagging strands differ in that _____.
the leading strand is synthesized in the same direction as the
movement of the replication fork, and the lagging strand is
synthesized in the opposite direction the leading strand is
synthesized by adding nucleotides to the 3' end of the growing
strand, and the lagging strand is synthesized by adding nucleotides
to the 5' end the lagging strand is synthesized
continuously, whereas the leading strand is synthesized in short
fragments that are ultimately stitched together the leading
strand is synthesized at twice the rate of the lagging strand
Which of the following statements describes chromatin?
Heterochromatin is composed of DNA, whereas euchromatin is
made of DNA and RNA. Both heterochromatin and euchromatin
are found in the cytoplasm. Heterochromatin is highly
condensed, whereas euchromatin is less compact. Euchromatin
is not transcribed, whereas heterochromatin is transcribed.
It became apparent to Watson and Crick after completion of their
model that the DNA molecule could carry a vast amount of hereditary
information in which of the following?
sequence of bases phosphate-sugar backbones
complementary pairing of bases side groups of
Which of the following investigators was (were) responsible for the
following discovery?In DNA from any species, the amount of
adenine equals the amount of thymine, and the amount of guanine equals
the amount of cytosine.
Alfred Hershey and Martha Chase Oswald Avery, Maclyn
McCarty, and Colin MacLeod Erwin Chargaff Matthew
Meselson and Franklin Stahl
At a specific area of a chromosome, the sequence of nucleotides below
is present where the chain opens to form a replication fork:
3' C C T A G G C T
G C A A T C C 5'
An RNA primer is formed starting at the underlined T (T) of the template. Which
of the following represents the primer sequence?
5' G C C T A G G 3' 5' A C G T T A G G 3' 5'
A C G U U A G G 3' 5' G C C U A G G 3'
Within a double-stranded DNA molecule, adenine forms hydrogen bonds
with thymine and cytosine forms hydrogen bonds with guanine. This
allows variable width of the double helix permits
complementary base pairing determines the tertiary
structure of a DNA molecule determines the type of protein
Cytosine makes up 42% of the nucleotides in a sample of DNA from an
organism. Approximately what percentage of the nucleotides in this
sample will be thymine?S
8% 16% 42% 58%
In a healthy cell, the rate of DNA repair is equal to the rate of DNA
mutation. When the rate of repair lags behind the rate of mutation,
what is a possible fate of the cell?
The cell can be transformed to a cancerous cell. RNA
may be used instead of DNA as inheritance material. The
cell will become embryonic. DNA synthesis will continue by
a new mechanism.
Who performed classic experiments that supported the semiconservative
model of DNA replication?
Watson and Crick Meselson and Stahl Hershey
and Chase Franklin and Wilkins
What is the function of topoisomerase?
relieving strain in the DNA ahead of the replication fork
elongating new DNA at a replication fork by adding nucleotides
to the existing chain unwinding of the double helix
stabilizing single-stranded DNA at the replication fork
A new DNA strand elongates only in the 5' to 3' direction because _____.
DNA polymerase begins adding nucleotides at the 5' end of the
template the polarity of the DNA molecule prevents addition
of nucleotides at the 3' end replication must progress
toward the replication fork DNA polymerase can add
nucleotides only to the free 3' end
In his transformation experiments, what did Griffith observe?
Mixing a heat-killed pathogenic strain of bacteria with a
living nonpathogenic strain can convert some of the living cells
into the pathogenic form. Mixing a heat-killed
nonpathogenic strain of bacteria with a living pathogenic strain
makes the pathogenic strain nonpathogenic. Infecting mice
with nonpathogenic strains of bacteria makes them resistant to
pathogenic strains. Mice infected with a pathogenic strain
of bacteria can spread the infection to other mice.
DNA contains the template needed to copy itself, but it has no
catalytic activity in cells. What catalyzes the formation of
phosphodiester bonds between adjacent nucleotides in the DNA polymer
ribozymes DNA polymerase ATP
Replication in prokaryotes differs from replication in eukaryotes for
which of the following reasons?
Prokaryotic chromosomes have histones, whereas eukaryotic
chromosomes do not. Prokaryotic chromosomes have a single
origin of replication, whereas eukaryotic chromosomes have
many. The rate of elongation during DNA replication is slower
in prokaryotes than in eukaryotes. Prokaryotes produce
Okazaki fragments during DNA replication, but eukaryotes do
Hershey and Chase used a DNA-based virus for their work. What would
the results have been if they had used an RNA virus?
With an RNA virus radioactive protein would have been in the
final pellet. With an RNA virus radioactive RNA would have
been in the final pellet. With an RNA virus neither sample
would have had a radioactive pellet. With an RNA virus the
protein shell would have been radioactive in both samples.