Download Campbell`s Biology, 9e (Reece et al.)

General Biology Lecture Exam #4
Due 12/10/13
Turn in scantron only!
2.5 pts each
1) In his transformation experiments, what did Griffith observe?
A) Mutant mice were resistant to bacterial infections.
B) Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living
cells into the pathogenic form.
C) Mixing a heat-killed nonpathogenic strain of bacteria with a living pathogenic strain makes the pathogenic strain
nonpathogenic.
D) Infecting mice with nonpathogenic strains of bacteria makes them resistant to pathogenic strains.
E) Mice infected with a pathogenic strain of bacteria can spread the infection to other mice.
2) 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?
A) 8%
B) 16%
C) 31%
D) 42%
E) It cannot be determined from the information provided.
3) 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?
A) sequence of bases
B) phosphate-sugar backbones
C) complementary pairing of bases
D) side groups of nitrogenous bases
E) different five-carbon sugars
4) In an analysis of the nucleotide composition of DNA, which of the following will be found?
A) A = C
B) A = G and C = T
C) A + C = G + T
D) G + C = T + A
5) What is meant by the description "antiparallel" regarding the strands that make up DNA?
A) The twisting nature of DNA creates nonparallel strands.
B) The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.
C) Base pairings create unequal spacing between the two DNA strands.
D) One strand is positively charged and the other is negatively charged.
E) One strand contains only purines and the other contains only pyrimidines.
6) An Okazaki fragment has which of the following arrangements?
A) primase, polymerase, ligase
B) 3' RNA nucleotides, DNA nucleotides 5'
C) 5' RNA nucleotides, DNA nucleotides 3'
D) DNA polymerase I, DNA polymerase III
E) 5' DNA to 3'
1
Copyright © 2011 Pearson Education, Inc.
7) Which enzyme catalyzes the elongation of a DNA strand in the 5' → 3' direction?
A) primase
B) DNA ligase
C) DNA polymerase III
D) topoisomerase
E) helicase
8) The leading and the lagging strands differ in that
A) 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.
B) 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.
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 at twice the rate of the lagging strand.
9) A new DNA strand elongates only in the 5' to 3' direction because
A) DNA polymerase begins adding nucleotides at the 5' end of the template.
B) Okazaki fragments prevent elongation in the 3' to 5' direction.
C) the polarity of the DNA molecule prevents addition of nucleotides at the 3' end.
D) replication must progress toward the replication fork.
E) DNA polymerase can only add nucleotides to the free 3' end.
10) What is the function of topoisomerase?
A) relieving strain in the DNA ahead of the replication fork
B) elongating new DNA at a replication fork by adding nucleotides to the existing chain
C) adding methyl groups to bases of DNA
D) unwinding of the double helix
E) stabilizing single-stranded DNA at the replication fork
11) What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?
A) It synthesizes RNA nucleotides to make a primer.
B) It catalyzes the lengthening of telomeres.
C) It joins Okazaki fragments together.
D) It unwinds the parental double helix.
E) It stabilizes the unwound parental DNA.
12) Which of the following nucleotide triplets best represents a codon?
A) a triplet separated spatially from other triplets
B) a triplet that has no corresponding amino acid
C) a triplet that has four nucleotides
D) a triplet in the same reading frame as an upstream AUG
E) a triplet in the same reading frame as an upstream UAA
2
Copyright © 2011 Pearson Education, Inc.
13) Alternative RNA splicing
A) is a mechanism for increasing the rate of transcription.
B) can allow the production of proteins of different sizes from a single mRNA.
C) can allow the production of similar proteins from different RNAs.
D) increases the rate of transcription.
E) is due to the presence or absence of particular snRNPs.
14) A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA
codon is
A) TTT.
B) UUA.
C) UUU.
D) AAA.
E) either UAA or TAA
15) Which of the following is the first event to take place in translation in eukaryotes?
A) elongation of the polypeptide
B) base pairing of activated methionine-tRNA to AUG of the messenger RNA
C) binding of the larger ribosomal subunit to smaller ribosomal subunits
D) covalent bonding between the first two amino acids
E) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA
16) Why might a point mutation in DNA make a difference in the level of protein's activity?
A) It might result in a chromosomal translocation.
B) It might exchange one stop codon for another stop codon.
C) It might exchange one serine codon for a different serine codon.
D) It might substitute an amino acid in the active site.
E) It might substitute the N-terminus of the polypeptide for the C-terminus.
17) A frameshift mutation could result from
A) a base insertion only.
B) a base deletion only.
C) a base substitution only.
D) deletion of three consecutive bases.
E) either an insertion or a deletion of a base.
Questions 18 and 19 need the table of codons.
18) A possible sequence of nucleotides in the template
strand of DNA that would code for the polypeptide
sequence phe-leu-ile-val would be
A) 5' TTG-CTA-CAG-TAG 3'.
B) 3' AAC-GAC-GUC-AUA 5'.
C) 5' AUG-CTG-CAG-TAT 3'.
D) 3' AAA-AAT-ATA-ACA 5'.
E) 3' AAA-GAA-TAA-CAA 5'.
3
Copyright © 2011 Pearson Education, Inc.
19) What amino acid sequence will be generated, based on the following mRNA codon sequence?
5' AUG-UCU-UCG-UUA-UCC-UUG 3'
A) met-arg-glu-arg-glu-arg
B) met-glu-arg-arg-glu-leu
C) met-ser-leu-ser-leu-ser
D) met-ser-ser-leu-ser-leu
E) met-leu-phe-arg-glu-glu
Use this representation to answer question 20.
DNA template strand
5' ____________________________ 3'
DNA complementary strand
3' ____________________________ 5'
20) Given the locally unwound double strand above, in which direction does the RNA polymerase move?
A) 3' → 5' along the template strand
B) 5' → 3' along the template strand
C) 3' → 5' along the complementary strand
D) 5' → 3' along the complementary strand
E) 5' → 3' along the double-stranded DNA
A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing
polypeptide on the other tRNA (#2) in the ribosome already. (Use this to answer 21—22).
21) Where does tRNA #2 move to after this bonding of lysine to the polypeptide?
A) A site
B) P site
C) E site
D) exit tunnel
E) directly to the cytosol
22) Which component of the complex described enters the exit tunnel through the large subunit of the ribosome?
A) tRNA with attached lysine (#1)
B) tRNA with polypeptide (#2)
C) tRNA that no longer has attached amino acid
D) newly formed polypeptide
E) initiation and elongation factors
23) A lack of which molecule would result in the cell's inability to "turn off" genes?
A) operon
B) inducer
C) promoter
D) ubiquitin
E) corepressor
24) Which of the following, when taken up by the cell, binds to the repressor so that the repressor no longer binds to the
operator?
A) ubiquitin
B) inducer
C) promoter
D) repressor
E) corepressor
4
Copyright © 2011 Pearson Education, Inc.
25) For a repressible operon to be transcribed, which of the following must occur?
A) A corepressor must be present.
B) RNA polymerase and the active repressor must be present.
C) RNA polymerase must bind to the promoter, and the repressor must be inactive.
D) RNA polymerase cannot be present, and the repressor must be inactive.
E) RNA polymerase must not occupy the promoter, and the repressor must be inactive.
26) Which of the following mechanisms is (are) used to coordinate the expression of multiple, related genes in
eukaryotic cells?
A) Genes are organized into clusters, with local chromatin structures influencing the expression of all the genes at once.
B) The genes share a common intragenic sequence, and allow several activators to turn on their transcription, regardless
of location.
C) The genes are organized into large operons, allowing them to be transcribed as a single unit.
D) A single repressor is able to turn off several related genes.
E) Environmental signals enter the cell and bind directly to promoters.
27) Two potential devices that eukaryotic cells use to regulate transcription are
A) DNA methylation and histone amplification.
B) DNA amplification and histone methylation.
C) DNA acetylation and methylation.
D) DNA methylation and histone modification.
E) histone amplification and DNA acetylation.
28) Tumor-suppressor genes
A) are frequently overexpressed in cancerous cells.
B) are cancer-causing genes introduced into cells by viruses.
C) can encode proteins that promote DNA repair or cell-cell adhesion.
D) often encode proteins that stimulate the cell cycle.
E) do all of the above.
29) Muscle cells differ from nerve cells mainly because they
A) express different genes.
B) contain different genes.
C) use different genetic codes.
D) have unique ribosomes.
E) have different chromosomes.
30) The functioning of enhancers is an example of
A) transcriptional control of gene expression.
B) a post-transcriptional mechanism to regulate mRNA.
C) the stimulation of translation by initiation factors.
D) post-translational control that activates certain proteins.
E) a eukaryotic equivalent of prokaryotic promoter functioning.
5
Copyright © 2011 Pearson Education, Inc.
31) What would occur if the repressor of an inducible operon were mutated so it could not bind the operator?
A) irreversible binding of the repressor to the promoter
B) reduced transcription of the operon's genes
C) buildup of a substrate for the pathway controlled by the operon
D) continuous transcription of the operon's genes
E) overproduction of catabolite activator protein (CAP)
32) Absence of bicoid mRNA from a Drosophila egg leads to the absence of anterior larval body parts and mirror-image
duplication of posterior parts. This is evidence that the product of the bicoid gene
A) is transcribed in the early embryo.
B) normally leads to formation of tail structures.
C) normally leads to formation of head structures.
D) is a protein present in all head structures.
E) leads to programmed cell death.
33) Which of the following statements about the DNA in one of your brain cells is true?
A) Most of the DNA codes for protein.
B) The majority of genes are likely to be transcribed.
C) Each gene lies immediately adjacent to an enhancer.
D) Many genes are grouped into operon-like clusters.
E) It is the same as the DNA in one of your heart cells.
34) The host range of a virus is determined by
A) the enzymes carried by the virus.
B) whether its nucleic acid is DNA or RNA.
C) the proteins in the host's cytoplasm.
D) the enzymes produced by the virus before it infects the cell.
E) the proteins on its surface and that of the host.
35) Which of the following is characteristic of the lytic cycle?
A) Many bacterial cells containing viral DNA are produced.
B) Viral DNA is incorporated into the host genome.
C) The viral genome replicates without destroying the host.
D) A large number of phages are released at a time.
E) The virus-host relationship usually lasts for generations.
36) Which of the following statements describes the lysogenic cycle of lambda (λ) phage?
A) After infection, the viral genes immediately turn the host cell into a lambda-producing factory, and the host cell then
lyses.
B) Most of the prophage genes are activated by the product of a particular prophage gene.
C) The phage genome replicates along with the host genome.
D) Certain environmental triggers can cause the phage to exit the host genome, switching from the lytic to the lysogenic.
E) The phage DNA is incorporated by crossing over into any nonspecific site on the host cell's DNA.
6
Copyright © 2011 Pearson Education, Inc.
37) A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell
contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. Which of the
following would be expected to occur?
A) The plants would develop some but not all of the symptoms of the TMV infection.
B) The plants would develop symptoms typically produced by viroids.
C) The plants would develop the typical symptoms of TMV infection.
D) The plants would not show any disease symptoms.
E) The plants would become infected, but the sap from these plants would be unable to infect other plants.
38) Which viruses have single-stranded RNA that acts as a template for DNA synthesis?
A) lytic phages
B) proviruses
C) viroids
D) bacteriophages
E) retroviruses
39) Which of the following can be effective in preventing the onset of viral infection in humans?
A) taking vitamins
B) getting vaccinated
C) taking antibiotics
D) applying antiseptics
E) taking nucleoside analogs that inhibit transcription
40) What are prions?
A) mobile segments of DNA
B) tiny molecules of RNA that infect plants
C) viral DNA that has had to attach itself to the host genome
D) misfolded versions of normal brain protein
E) viruses that invade bacteria
41) Which of the following series best reflects what we know about how the flu virus moves between species?
A) An avian flu virus undergoes several mutations and rearrangements such that it is able to be transmitted to other
birds and then to humans.
B) The flu virus in a pig is mutated and replicated in alternate arrangements so that humans who eat the pig products
can be infected.
C) A flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus differently and then pass it
back to humans.
D) An influenza virus gains new sequences of DNA from another virus, such as a herpesvirus; this enables it to be
transmitted to a human host.
E) An animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates
and is passed to a new species such as a bird, the virus mutates and can be transmitted to humans.
7
Copyright © 2011 Pearson Education, Inc.
Use this figure to answer question 42—43.
42) Which of the three types of viruses shown above
would you expect to include glycoproteins?
A) I only
B) II only
C) III only
D) I and II only
E) all three
43) Which of the three types of viruses shown above
would you expect to include a capsid(s)?
A) I only
B) II only
C) III only
D) I and II only
E) all three
44) Which of the following characteristics, structures, or processes is common to both bacteria and viruses?
A) metabolism
B) ribosomes
C) genetic material composed of nucleic acid
D) cell division
E) independent existence
45) To cause a human pandemic, the H5N1 avian flu virus would have to
A) spread to primates such as chimpanzees.
B) develop into a virus with a different host range.
C) become capable of human-to-human transmission.
D) arise independently in chickens in North and South America.
E) become much more pathogenic.
46) 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.
A) 2, 1, 4
B) 1, 3, 2, 4
C) 3, 4, 1, 2
D) 3, 4, 2
E) 2, 3, 4
47) 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.
8
Copyright © 2011 Pearson Education, Inc.
48) The reason for using Taq polymerase for PCR is that
A) it is heat stable and can withstand the temperature changes of the cycler.
B) only minute amounts are needed for each cycle of PCR.
C) it binds more readily than other polymerases to primer.
D) it has regions that are complementary to primers.
E) All of these are correct.
49) Which of the following modifications is most likely to alter the rate at which a DNA fragment moves through a gel
during electrophoresis?
A) altering the nucleotide sequence of the DNA fragment
B) mutating a single base within the DNA fragment
C) increasing the concentration of the DNA fragment
D) decreasing the length of the DNA fragment
E) decreasing the concentration of the DNA fragment
50) In 1997, Dolly the sheep was cloned. Which of the following processes was used?
A) use of mitochondrial DNA from adult female cells of another ewe
B) replication and dedifferentiation of adult stem cells from sheep bone marrow
C) separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe
D) fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate
E) isolation of stem cells from a lamb embryo and production of a zygote equivalent
51) Which of the following problems with animal cloning might result in premature death of the clones?
A) use of pluripotent instead of totipotent stem cells
B) use of nuclear DNA as well as mtDNA
C) abnormal regulation due to variant methylation
D) the indefinite replication of totipotent stem cells
E) abnormal immune function due to bone marrow dysfunction
52) What is the major difference between embryonic stems cells and adult stem cells?
A) Differ in the number and type of differentiated cell types they can become.
B) Differ in restriction enzymes and polymerases available for cloning.
C) Differ in DNA sequence.
D) All of the above are true.
E) No difference.
53) The first cloned cat, called Carbon Copy, was a calico, but she looked significantly different from her female parent.
Why?
A) The environment, as well as genetics, affects phenotypic variation.
B) Fur color genes in cats are influenced by differential acetylation patterns.
C) Cloned animals have been found to have a higher frequency of transposon activation
D) X inactivation in the embryo is random and produces different patterns.
E) The telomeres of the parent's chromosomes were shorter than those of an embryo.
9
Copyright © 2011 Pearson Education, Inc.
Use this figure to answer question 54.
54) Which enzyme was used to produce the molecule?
A) ligase
B) transcriptase
C) a restriction enzyme
D) RNA polymerase
E) DNA polymerase
55) A paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo (a bird). To
compare a specific region of the DNA from the sample with DNA from living birds, which of the following would be most
useful for increasing the amount of dodo DNA available for testing?
A) RFLP analysis
B) polymerase chain reaction (PCR)
C) electroporation
D) gel electrophoresis
E) sequencing
56) Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a
restriction enzyme?
A) AAGG
TTCC
B) AGTC
TCAG
C) GGCC
CCGG
D) ACCA
TGGT
E) AAAA
TTTT
10
Copyright © 2011 Pearson Education, Inc.