.Which of the following best describes why the polymerase chain
reaction is a standard technique used in molecular biology research?
A. It uses inexpensive materials and produces perfect
results
B. It can purify specific section of a DNA molecule
C. It can produce large amounts of specific DNA sequences
D. It can duplicate the entire human genome
E. It can
produce large amounts of mRNA
C
DNA microarrays have made a huge impact on genomic studies because
they
A) can be used to eliminate the function of any gene in the
genome.
B) can be used to introduce entire genomes into
bacterial cells.
C) allow the expression of many or even all of
the genes in the genome to be compared at once.
D) allow
physical maps of the genome to be assembled in a very short time.
E) dramatically enhance the efficiency of restriction enzymes.
C
23) Which of the following produces multiple identical copies of a
gene for basic research or for large-scale production of a gene
product?
A) restriction enzymes
B) gene cloning
C) DNA
ligase
D) gel electrophoresis
E) reverse transcriptase
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) collections of genes
who expression is controlled by the regulatory proteins
E)
identical or similar genes that have evolved by gene duplication
E
What is an important consequence of sequence variation in DNA acted upon differently by natural selection in different environments of tandem repeat DNA?
It makes it useful for DNA fingerprinting
A student uses restriction enzymes to cut a DNA molecule into
fragments. The digested DNA is loaded into the wells of an agarose gel
and the gel is subjected to an electric current. Upon completion of
the run, the gel is stained.
111. The rate of migration of the
DNA fragments through the agarose gel is determined by the
(A)
ratio of adenine to cytosine in the fragment
(B) presence of
hydrogen bonds between base pairs
(C) length of time the
electrophoresis unit is allowed to operate
(D) number of
nucleotides in the fragment
(E) volume of the starting sample
D
A student uses restriction enzymes to cut a DNA molecule into
fragments. The digested DNA is loaded into the wells of an agarose gel
and the gel is subjected to an electric current. Upon completion of
the run, the gel is stained.
112. Which of the following
is true of the dye used to stain the fragments?
(A) It
increases the contrast between the agar and the DNA fragments.
(B) It must be accounted for when calculating the molecular
weight of the fragments.
(C) Its charged areas interfere with
the migration of the DNA.
(D) It is bonded only to the sticky
ends of the fragments and can directly determine the sequence of the
DNA fragments.
(E) It gives a three-dimensional view of the
structure of the DNA fragments.
A
A student uses restriction enzymes to cut a DNA molecule into
fragments. The digested DNA is loaded into the wells of an agarose gel
and the gel is subjected to an electric current. Upon completion of
the run, the gel is stained.
113. The type and density
of the gel are important because
(A) they influence the rate of
migration of the fragments
(B) they may cause some DNA
molecules to replicate
(C) some DNA nucleotides may be lost due
to chemical reactions with the gel
(D) some DNA molecules may
sink to the bottom and not migrate
(E) some DNA molecules may cross-link
A
A student uses restriction enzymes to cut a DNA molecule into
fragments. The digested DNA is loaded into the wells of an agarose gel
and the gel is subjected to an electric current. Upon completion of
the run, the gel is stained.
114. The procedures
described can be used to do all of the following EXCEPT
(A)
isolate and purify certain DNA fragments
(B) synthesize novel
DNA molecules
(C) study the activity of restriction enzymes
(D) calculate the size of DNA fragments
(E) identify the
source of DNA material
B
65. Enzyme used to position nucleotides during DNA replication
(A) DNA ligase
(B) DNA polymerase
(C) RNA polymerase
(D) Restriction enzyme
(E) Reverse transcriptase
B
73. Used to carry the genetic code
(A) Proteins
(B) Carbohydrates
(C) Nucleic acids
(D) Lipids
(E) Steroids
C
Porkaryotic and eukaryotic cells generally have wich of the following
features in common?
a. A membrane-bound nucleus
b. A cell
wall made of cellulose
c. Ribosomes
d. Flagella or cilia
that contain microtubules
e. Linear chromosomes made of DNA and protein
C
Plates that have only ampicillin-resistant bacteria growing include which of the following? (A) I only (B) III only (C) IV only (D) I and II
c
Which of the following best explains why there is no growth on plate II? (A) The initial E. coli culture was not ampicillinresistant. (B) The transformation procedure killed the bacteria. (C) Nutrient agar inhibits E. coli growth. (D) The bacteria on the plate were transformed.
a
Plates I and III were included in the experimental design in order to (A) demonstrate that the E. coli cultures were viable (B) demonstrate that the plasmid can lose its ampr gene (C) demonstrate that the plasmid is needed for E. coli growth (D) prepare the E. coli for transformation
a
Which of the following statements best explains why there are fewer colonies on plate IV than on plate III? (A) Plate IV is the positive control. (B) Not all E. coli cells are successfully transformed. (C) The bacteria on plate III did not mutate. (D) The plasmid inhibits E. coli growth.
b
In a second experiment, the plasmid contained the gene for human insulin as well as the ampr gene. Which of the following plates would have the highest percentage of bacteria that are expected to produce insulin? (A) I only (B) III only (C) IV only (D) I and III
c
Sticky ends are
a. produced by PCR
b. used by mRNA to attach to ribosomes
c. produced by the action of DNA ligase
d. unpaired DNA nucleotides
C
The process of making multiple copies of a gene by inserting it into a host genome and culturing the host is an example of
gene cloning
A collection of cloned DNA fragments that include an organism's entire genome is called a
genomic library
Sticky ends are
Single-stranded ends of fragments of double-stranded DNA
What name is given to a region of DNA that varies from person to person
genetic marker
3) What is the most logical sequence of steps for splicing foreign
DNA into a plasmid and inserting the plasmid into a bacterium?
I. Transform bacteria with a recombinant DNA molecule.
II.
Cut the plasmid DNA using restriction enzymes.
III. Extract
plasmid DNA from bacterial cells.
IV. Hydrogen-bond the plasmid
DNA to nonplasmid DNA fragments.
V. Use ligase to seal plasmid
DNA to nonplasmid DNA.
A) I, II, IV, III, V
B) II,
III, V, IV, I
C) III, II, IV, V, I
D) III, IV, V, I, II
E) IV, V, I, II, III
C
4) A principal problem with inserting an unmodified mammalian gene
into a BAC, and then getting that gene expressed in bacteria, is that
A) prokaryotes use a different genetic code from that of
eukaryotes.
B) bacteria translate polycistronic messages only.
C) bacteria cannot remove eukaryotic introns.
D) bacterial
RNA polymerase cannot make RNA complementary to mammalian DNA.
E) bacterial DNA is not found in a membrane-bounded nucleus and
is therefore incompatible with mammalian DNA.
C
16) Why is it so important to be able to amplify DNA fragments when
studying genes?
A) DNA fragments are too small to use
individually.
B) A gene may represent only a millionth of the
cell's DNA.
C) Restriction enzymes cut DNA into fragments that
are too small.
D) A clone requires multiple copies of each gene
per clone.
E) It is important to have multiple copies of DNA in
the case of laboratory error.
B
23) Which of the following produces multiple identical copies of a
gene for basic research or for large-scale production of a gene
product?
A) restriction enzymes
B) gene cloning
C) DNA
ligase
D) gel electrophoresis
E) reverse transcriptase
B
26) Which of the following cuts DNA molecules at specific locations?
A) restriction enzymes
B) gene cloning
C) DNA
ligase
D) gel electrophoresis
E) reverse transcriptase
A
5. Multigene families are
A) groups of enhancers that control
transcription
B) usually clustered at the telomeres
C)
equivalent to the operons of prokaryotes
D) collections of genes
who expression is controlled by the regulatory proteins
E)
identical or similar genes that have evolved by gene duplication
E
21) What characteristic of short tandem repeat DNA makes it useful
for DNA fingerprinting?
A) The number of repeats varies widely
from person to person or animal to animal.
B) The sequence of DNA
that is repeated varies significantly from individual to
individual.
C) The sequence variation is acted upon differently
by natural selection in different environments.
D) Every racial
and ethnic group has inherited different short tandem repeats.
A
24) What is it that can be duplicated in a genome?
A) DNA
sequences above a minimum size only
B) DNA sequences below a
minimal size only
C) entire chromosomes only
D) entire sets
of chromosomes only
E) sequences, chromosomes, or sets of chromosomes
E
26) Unequal crossing over during Prophase I can result in one sister
chromosome with a deletion
and another with a duplication. A
mutated form of hemoglobin, known as hemoglobin Lepore, is
known
in the human population. Hemoglobin Lepore has a deleted set of amino
acids. If it was
caused by unequal crossing over, what would be
an expected consequence?
A) If it is still maintained in the
human population, hemoglobin Lepore must be selected for
in
evolution.
B) There should also be persons born with, if
not living long lives with, an anti-Lepore mutation
or
duplication.
C) Each of the genes in the hemoglobin gene family
must show the same deletion.
B
27) When does exon shuffling occur?
A) during splicing of
DNA
B) during mitotic recombination
C) as an alternative
splicing pattern in post-transcriptional processing
D) as an
alternative cleavage or modification post-translationally
E) as
the result of faulty DNA repair
C
Multigene families include two or more nearly identical genes or
genes sharing nearly identical
sequences. A classical example is
the set of genes for globin molecules, including genes on
human
chromosomes 11 and 16.
How might identical and
obviously duplicated gene sequences have gotten from
one
chromosome to another?
a. normal meitoic recombination
b. normal mitotic recombination between sister chromatids
c. transcription followed by recombination
d. chromosomal translocation
D
Multigene families include two or more nearly identical genes or
genes sharing nearly identical
sequences. A classical example is
the set of genes for globin molecules, including genes on
human
chromosomes 11 and 16.
Several of the
different globin genes are expressed in humans, but at different
times in
development. What mechanism could allow for this?
A) exon shuffling
B) intron activation
C) pseudogene activation
D) differential translation of mRNAs
E) differential gene regulation over time
E
B
24) Which of the following seals the sticky ends of restriction
fragments to make recombinant DNA?
A) restriction enzymes
B) gene cloning
C) DNA ligase
D) gel
electrophoresis
E) reverse transcriptase
C
Which of the following best describes the complete sequence of steps
occurring during every cycle of PCR?
1. The primers hybridize to
the target DNA.
2. The mixture is heated to a high
temperature to denature the double-stranded target DNA.
3. Fresh DNA polymerase is added.
4. DNA polymerase
extends the primers to make a copy of the target DNA.
2,1,4
Some strains of the bacterium Streptococcus pyogenes secrete poisonous substances called exotoxins. The genes encoding the exotoxins are though to have originated in the bacteriophages, which are viruses that infect bacteria. Which of the following is the most likely mechanism by which the S. pyogenes acquired the ability to produce the extoxins?
A. Bacteriophages engulfed cellular debris from dead bacteria
B. Bacteriophages in the environment activated debris from dead bacteria
C. Bacteriophage DNA became integrated in the bacterial chromosomes
D. Bacteriophage proteins were absorbed into bacteria cells by endocytosis
C