Transcript Slide 1

A prokaryotic cell has which of the following?
a. centrioles
b. lysosomes
c. plasma membrane
d. mitochondria
Answer: c
Which of these is a true statement?
a. Both plasmids and viruses can serve as
vectors.
b. Plasmids can carry recombinant DNA but
viruses cannot.
c. Vectors carry only the foreign gene into the
host cell.
d. All of these statements are true.
Answer: a
Which of these is found in all viruses?
a. envelope, nucleic acid, capsid
b. DNA, RNA, proteins
c. proteins and a nucleic acid
d. proteins, nucleic acids, carbohydrates, and
lipids
e. reverse transcriptase
Answer: c
a. DNA ligase
b. DNA polymerase
c. RNA polymerase
d. Restriction enzyme
e. Reverse transcriptase
1. Enzyme found in retroviruses that produce
DNA from an RNA template.
Answer: e
2. Enzyme used during replication to attach
Okazaki fragments to each other. Answer: a
3. Enzyme used during transcription to produce
mRNA.
Answer: c
Chemosynthetic bacteria
a. are autotrophic
b. use the rays of the sun to acquire energy.
c. oxidize inorganic compounds to acquire
energy.
d. give off oxygen.
e. Both a and c are correct.
f. Both b and d are correct
Answer: e
Which of the following is NOT a form of
genetic recombination in bacteria?
a. binary fission
b. conjugation
c. transduction
d. transformation
e. All are forms of recombination.
Answer: a
A bacterium produces vitamins for a host
while gaining a habitat. This relationship is
a. commensalism.
b. mutualism.
c. parasitism.
d. predation.
e. competition.
Answer: b
Which of the following is NOT a correct
contrast between bacteria and eukaryotes?
Bacteria
a. binary fission
b. nucleoid
c. asexual only
d. nonmotile
e. no membrane bound
organelles
Answer: d
Eukaryotes
mitotic cell division
nucleus
asexual and sexual
motile
membrane bound
organelles
Which of these is (are) a true statement(s)?
a. Archaea are in a separate kingdom.
b. Archaea are in their own domain.
c. Archaea are found in most every habitat.
d. Archaea are found in extreme habitats like
swamps, salty lakes, hot, acidic aquatic
habitats.
e. Both b and d are correct.
Answer: e
The binding of an active repressor
molecule at this site prevents transcription.
a. operon
b. operator
c. promotor
d. repressor
e. corepressor
Answer: b
The working of the lac operon is important for
which of the following reasons?
A. It represents a principal means by which genes
are regulated in prokaryotes.
B. It represents a principal means by which genes
are regulated in eukaryotes.
C. It illustrates the complexities of rRNA transcription.
D. It provided the first clues to how DNA replication
is controlled during the cell cycle.
E. The understanding of it lead to the development
of an economical means for the biological
production of lactose.
Answer: a
Which of the following statements about plasmids
is correct?
a.
b.
c.
d.
e.
They are synthesized in the endoplasmic reticulum.
They are found only in eukaryotic cells.
They are composed of RNA.
They are larger in size than bacterial chromosomes.
They are self-replicating.
Answer: e
Which of the following is NOT a potential control
mechanism for regulation of gene expression in
eukaryotic organisms?
a.
b.
c.
d.
The degradation of RNA
The transport of mRNA from the nucleus
The lactose operon
Transcription
Answer: c
a. Transcription
b. Translation
c. Transposon
d. DNA methylation
e. Histone acetylation
1. A mobile segment of DNA that travels from one
location on a chromosome to another, one
element of genetic change. Answer: c Answer: d
2. The addition of groups to certain bases of DNA
after DNA synthesis; this is thought to be an
important control mechanism for gene expression.
3. The synthesis of polypeptides from the genetic
Answer: b
information coded in mRNA.
The actions of which of the following enzymes
are responsible for ensuring that chromosomes do
not decrease in length with every round of
replication?
a.
b.
c.
d.
Telomerase
DNA ligase
Helicase
Primase
Answer: a
a. tRNA
b. mRNA
c. Poly-A tail
d. RNA polymerase
e. r RNA
1. An example of post-transcriptional modification
Answer: c
2. Binds to the promoter on DNA to initiate
transcription.
Answer: d
Answer: e
3. Along with proteins, comprises ribosomes
Answer: a
4. Binds to free amino acids in the cytoplasm
The expression of eukaryotic genes can be
Controlled at all of the following stages of
Protein synthesis EXCEPT
a.
b.
c.
d.
Initiation of transcription
RNA processing
Degradation of protein
Acetylation of DNA
Answer: d
One of the characteristics of retrotransposons is that
a. They code for an enzyme that synthesizes DNA
using an RNA template.
b. They are found only in animal cells
c. They contribute a significant portion of the genetic
variability seen in a population of gametes
d. They generally move in a cut and paste
mechanism
Answer: a
Which of the following shows the steps of an HIV
viral infection in the proper order?
a. Virus locates cell, enters nucleus, alters host cell
DNA, destroys the cell membrane
b. Virus locates cell, alters host DNA, host cell
produces copies of virus, copies enter host
cell nucleus, nucleus leaves cell
c. Virus locates cell, penetrates cell membrane,
enters nucleus, alters host cell DNA, host cell
produces copies of virus
d. Virus locates cell, enters cell, changes RNA to DNA,
host cell produces copies of virus Answer: d
Which of the following is a difficulty in getting
prokaryotic cells to express eukaryotic genes?
a. The signals that control gene expression are
different and prokaryotic promoter regions
must be added to the vector.
b. The genetic code differs because prokaryotes
substitute the base uracil for thymine.
c. Prokaryotic cells cannot transcribe introns
because their genes do not have them.
d. The ribosomes of prokaryotes are not large
enough to handle long eukaryotic genes.
Answer: a
Lactose digestion in E. coli begins with its hydrolysis by the enzyme bgalactosidase. The gene encoding b-galactosidase, lacZ, is part of a
coordinately regulated operon containingother genes required for lactose
utilization. Which of the following figures correctly depicts the
interactions at the lac operon when lactose is NOT being utilized? (The
legend below defines the shapes of the molecules illustrated in the
options.)
A.
C.
B.
D.
Answer: D
Arctic foxes typically have a white coat in the winter. In summer,
when there is no snow on the ground, the foxes typically have a darker
coat. Which of the following is most likely responsible for the
seasonal change in coat color?
a. The decrease in the amount of daylight in winter causes
a change in gene expression, which results in the foxes
growing a lighter appearing coat.
b. The diet of the foxes in summer lacks a particular
nutrient, which causes the foxes to lose their white coat
and grow a darker colored coat.
c. Competition for mates in the spring causes each fox to
increase its camouflage with the environment by
producing a darker appearing coat.
d. The lower temperatures in winter denature the pigment
molecules in the arctic fox coat, causing the coat to
become lighter in color.
Answer: a
During development, individual cells of
the same organism begin to produce
different proteins because
a. the cells have different numbers of
chromosomes.
b. not all cells can synthesize protein.
c. specific genes are activated in the
cells.
b. the cells have different kinds and
amounts of DNA
Answer: c
According to the Jacob-Monod model of
the lac operon, the regulator gene does
which of the following?
a. Specifies the amino acid sequence of
the enzyme.
b. Controls the activity of histones.
c. Determines whether promoter genes
will be translated.
d. Directs the synthesis of a repressor
protein.
Answer: d
A tobacco plant can be made to express a gene from
fireflies, resulting in the emission of light. Which of
the following is the basis for this phenomenon?
a. Chloroplasts can be made to produce light if
firefly proteins are injected into plant cells.
b. Fireflies and tobacco plants share a recent
common ancestor.
c. Transcription and translation are
fundamentally similar in both fireflies and
tobacco plants.
d. Most enzymes in fireflies have the same
amino acid sequence as the enzymes in
tobacco plants.
Answer: c
The FtsZ protein is present in prokaryotes and in
chloroplasts. The protein is structurally and
functionally similar to tubulin proteins of eukaryotic
cells. Which of the following is a likely conclusion to
draw from this information?
A. FtsZ and tubulin proteins were both present in a
common ancestor.
B. Microtubules are involved in the mechanics of
photosynthesis.
C. Tubulin genes are evolutionarily derived from
the gene that codes for the FtsZ protein.
D. The sequences of the genes encoding the FtsZ
and tubulin proteins are identical.
Answer: C
The human genome appears to have only one-third
more genes than the simple nematode C elegans.
Which of the following best explains how the more
complex humans can have relatively few genes?
A. The unusually long introns in human genes are
involved in regulation of gene expression.
B. More than one polypeptide can be produced from
a gene by alternative splicing.
C. Human genes code for many more types of
domains.
D. The large number of SNPs (single nucleotide
polymorphisms) in the human genome provides
for a great deal of genetic variability.
Answer: B
Multigene families are
A. groups of enhancers that control
transcription.
B. usually clustered at the telomeres.
C. equivalent to the operons of
prokaryotes.
D. sets of identical or similar genes
that have evolved by duplication.
Answer: D
Transposons
A. Are found only in animal cells.
B. Generally move by a cut and paste
mechanism.
C. Contribute a significant portion of
the genetic variability seen within
a population of gametes.
D. Amplification is dependent on a
retrovirus.
Answer: B
Comparative genomics
A. assigns functions to the products of
genes.
B. assigns functions to regulatory
sequences.
C. compares genes in different
organisms to see how those
organisms are related physiologically.
D. Both a and c
Answer: C