10_Test_Bank
Biology: Concepts and Connections, 6e (Campbell)
Chapter 10
Molecular Biology of the Gene
Multiple-Choice Questions
1) Which of the following statements regarding viruses is false?
A) A virus is generally considered to be alive because it is cellular and can reproduce on its own.
B) The host cell provides most of the tools and raw materials for viral multiplication.
C) Once a person is infected with the herpesvirus, the virus remains permanently latent in the body.
D) Viruses can enter a host cell w hen the protein molecules on the outside of the virus fit into receptor molecules on the
outside of the cell.
E) Herpesviruses and the virus that causes AIDS can remain latent inside our cells for long periods of time.
Answer: A
Topic: Opening Essay
Skill: Factual Recall
2) Which of the following people conducted the experiments that demonstrated that DNA is the genetic material of bacteriophages?
A) Watson and Crick
B) Hershey and Chase
C) Franklin
D) Griffith
E) Pauling
Answer: B
Topic: 10.1
Skill: Factual Recall
3) One type of virus that infects bacteria is called a
A) phage.
B) mage.
C) rhinovirus.
D) filovirus.
E) coronavirus.
Answer: A
Topic: 10.1
Skill: Factual Recall
4) When a T2 bacteriophage infects an Escherichia coli cell, which part of the phage enters the bacterial cytoplasm?
A) the whole phage
B) only the RNA
C) only the DNA
D) the protein "headpiece" and its enclosed nucleic acid
E) the tail fibers
Answer: C
Topic: 10.1
Skill: Factual Recall
5) The way that genetic material of a bacteriophage enters a bacterium is most like the way that
A) a drug is injected with a hypodermic needle.
B) a person swallows a pill.
C) skin lotion is rubbed onto the hands.
D) sugar dissolves in water.
E) water soaks into a sponge.
Answer: A
Topic: 10.1
Skill: Conceptual Understanding
6) The monomers of DNA and RNA are
A) amino acids.
B) monosaccharides.
C) nucleotides.
D) fatty acids.
E) nucleic acids.
Answer: C
Topic: 10.2
Skill: Factual Recall
7) Which of the following statements regarding DNA is false?
A) DNA uses the sugar deoxyribose.
B) DNA uses the nitrogenous base uracil.
C) DNA is a nucleic acid.
D) One DNA molecule can include four different nucleotides in its structure.
E) DNA molecules have a sugar-phosphate backbone.
Answer: B
Topic: 10.2
Skill: Factual Recall
8) Which of the following statements regarding RNA is false?
A) RNA uses the sugar dextrose.
B) RNA uses the nitrogenous base uracil.
C) RNA is a nucleic acid.
D) One RNA molecule can include four different nucleotides in its structure.
E) RNA molecules have a sugar-phosphate backbone.
Answer: A
Topic: 10.2
Skill: Factual Recall
9) Which of the following statements regarding the structure of DNA is false?
A) The DNA molecule has a uniform diameter.
B) In a DNA molecule, adenine bonds to thymine and guanine to cytosine.
C) The DNA molecule is in the form of a double helix.
D) Watson and Crick received a Nobel Prize for their description of the structure of DNA.
E) The sequence of nucleotides along the length of a DNA strand is restricted by the base-pairing rules.
Answer: E
Topic: 10.3
Skill: Factual Recall
10) How would the shape of a DNA molecule change if adenine paired with guanine and cytosine paired with thymine?
A) The DNA molecule would be longer.
B) The DNA molecule would be shorter.
C) The DNA molecule would be circular.
D) The DNA molecule would have regions where no base-pairing would occur.
E) The DNA molecule would have irregular widths along its length.
Answer: E
Topic: 10.3
Skill: Conceptual Understanding
11) The shape of a DNA molecule is most like
A) a set of railroad tracks.
B) a diamond ring.
C) a twisted rope ladder.
D) a gold necklace.
E) the letter X.
Answer: C
Topic: 10.3
Skill: Conceptual Understanding
12) Which of the following statements regarding a DNA double helix is always true?
A) The amount of adenine is equal to the amount of uracil, and the amount of guanine is equal t o the amount of cytosine.
B) The amount of adenine is equal to the amount of thymine, and the amount of guanine is equal to the amount of uracil.
C) The amount of adenine is equal to the amount of guanine, and the amount of thymine is equal to the amount of
cytosine.
D) The amount of adenine is equal to the amount of cytosine, and the amount of guanine is equal to the amount of
thymine.
E) The amount of adenine is equal to the amount of thymine, and the amount of guanine is equal to the amoun t of
cytosine.
Answer: E
Topic: 10.3
Skill: Factual Recall
13) DNA replication
A) occurs through the addition of nucleotides to the end of the DNA molecule.
B) results in the formation of four new DNA strands.
C) produces two daughter DNA molecules that are complementary to each other.
D) uses each strand of a DNA molecule as a template for the creation of a new strand.
E) begins when two DNA molecules join together to exchange segments.
Answer: D
Topic: 10.4
Skill: Factual Recall
14) If one strand of DNA is CGGTAC, the corresponding strand would be
A) GCCTAG.
B) CGGTAC.
C) GCCAUC.
D) TAACGT.
E) GCCATG.
Answer: E
Topic: 10.4
Skill: Application
15) The copying mechanism of DNA is most like
A) using a photographic negative to make a positive image.
B) mixing flour, sugar, and water to make bread dough.
C) joining together links to make a chain.
D) carving a figure out of wood.
E) threading beads onto a string.
Answer: A
Topic: 10.4
Skill: Conceptual Understanding
16) When one DNA molecule is copied to make two DNA molecules, the new DNA contains
A) none of the parent DNA.
B) 25% of the parent DNA.
C) 50% of the parent DNA.
D) 75% of the parent DNA.
E) 100% of the parent DNA
Answer: C
Topic: 10.4
Skill: Factual Recall
17) Multiple origins of replication on the DNA molecules of eukaryotic cells serve to
A) remove errors in DNA replication.
B) create multiple copies of the DNA molecule at the same time.
C) shorten the time necessary for DNA replication.
D) reduce the number of "bubbles" that occur in the DNA molecule during replication.
E) assure the correct orientation of the two strands in the newly growing double helix.
Answer: C
Topic: 10.5
Skill: Factual Recall
18) Which of the following enzymes catalyzes the elongation of a new DNA strand?
A) helicase
B) primase
C) ligase
D) single-stranded binding protein
E) DNA polymerase
Answer: E
Topic: 10.5
Skill: Factual Recall
19) Why does a DNA strand grow only in the 5' to 3' direction?
A) because DNA polymerases can only add nucleotides to the 3' end of the growing molecule
B) because DNA polymerases can only add nucleotides to the 5' end of the growing molecule
C) because mRNA can only read a DNA molecule in the 5' to 3' direction
D) because the DNA molecule only unwinds in the 5' to 3' direction
E) because DNA polymerase requires the addition of a starter nucleotide at the 5' end
Answer: A
Topic: 10.5
Skill: Factual Recall
20) Which of the following options best depicts the flow of information when a gene directs the synthesis of a cellular component?
A) RNA → DNA → RNA → protein
B) DNA → RNA → protein
C) protein → RNA → DNA
D) DNA → amino acid → RNA → protein
E) DNA → tRNA → mRNA → protein
Answer: B
Topic: 10.6
Skill: Factual Recall
21) The transfer of genetic information from DNA to RNA is called
A) translation.
B) transcription.
C) initiation.
D) elongation.
E) promotion.
Answer: B
Topic: 10.6
Skill: Factual Recall
22) The "one gene-one polypeptide" theory states that
A) the synthesis of each gene is catalyzed by one specific enzyme.
B) the synthesis of each enzyme is catalyzed by one specific gene.
C) the function of an individual gene is to dictate the production of a specific polypeptide.
D) each polypeptide catalyzes a specific reaction.
E) the function of each polypeptide is to regulate the synthesis of each corresponding gene.
Answer: C
Topic: 10.6
Skill: Conceptual Understanding
23) Experiments have demonstrated that the "words" of the genetic code (the units that specify amino acids) are
A) single nucleotides.
B) two-nucleotide sequences.
C) three-nucleotide sequences.
D) nucleotide sequences of various lengths.
E) enzymes.
Answer: C
Topic: 10.7
Skill: Factual Recall
24) The directions for each amino acid in a polypeptide are indicated by a codon that consists of ________ nucleotide(s) in an RNA molecule.
A) 5
B) 4
C) 3
D) 2
E) 1
Answer: C
Topic: 10.8
Skill: Factual Recall
25) We would expect that a 15-nucleotide sequence will direct the production of a polypeptide that consists of
A) 2 amino acids.
B) 3 amino acids.
C) 4 amino acids.
D) 5 amino acids.
E) 6 amino acids.
Answer: C
Topic: 10.8
Skill: Application
26) A base substitution mutation in a gene does not always result in a different protein. Which of the following factors could account for this?
A) the fact that the mutation affects only the sequence of the protein's amino acids, so the protein stays the same
B) the double-ring structure of adenine and guanine
C) a correcting mechanism that is part of the mRNA molecule
D) the fact that such mutations are usually accompanied by a complementary deletion
E) the fact that some amino acids are specified from more than one codon
Answer: E
Topic: 10.8
Skill: Conceptual Understanding
27) Which of the following enzymes catalyzes the linking together of RNA nucleotides to form RNA?
A) RNA polymerase
B) RNA ligase
C) a ribozyme
D) reverse transcriptase
E) tRNA
Answer: A
Topic: 10.9
Skill: Factual Recall
28) Which of the following occurs when RNA polymerase attaches to the promoter DNA?
A) elongation of the growing RNA molecule
B) termination of the RNA molecule
C) addition of nucleotides to the DNA template
D) initiation of a new RNA molecule
E) initiation of a new polypeptide chain
Answer: D
Topic: 10.9
Skill: Conceptual Understanding
29) ________ marks the end of a gene and causes transcription to stop.
A) RNA polymerase
B) RNA ligase
C) A terminator
D) Reverse transcriptase
E) Methionine
Answer: C
Topic: 10.9
Skill: Factual Recall
30) Where do transcription and translation occur in prokaryotic cells?
A) on the plasma membrane
B) in the nucleus
C) in the cytoplasm
D) in chromatophores
E) in the cell wall
Answer: C
Topic: 10.10
Skill: Factual Recall
31) Which of the following statements about eukaryotic RNA is true?
A) Introns are added to the RNA.
B) Exons are spliced together.
C) A small cap of extra nucleotides is added to both ends of the RNA.
D) A long tail of extra nucleotides is removed from the 5' end of the RNA.
E) The modified RNA molecule is transported into the nucleus.
Answer: B
Topic: 10.10
Skill: Factual Recall
32) Which of the following takes place during translation?
A) the conversion of genetic information from the language of nucleic acids to the language of proteins
B) the conversion of genetic information from DNA nucleotides into RNA nucleotides
C) the addition of nucleotides to a DNA template
D) the conversion of genetic information from the language of proteins to the language of enzymes
E) DNA replication
Answer: A
Topic: 10.11
Skill: Conceptual Understanding
33) Which of the following is a function of tRNA?
A) joining to several types of amino acid
B) recognizing the appropriate anticodons in mRNA
C) transferring nucleotides to rRNA
D) helping to translate codons into nucleic acids
E) joining to only one specific type of amino acid
Answer: E
Topic: 10.11
Skill: Factual Recall
34) Which of the following is not needed in order for translation to occur?
A) DNA template
B) ribosomes
C) tRNA
D) various enzymes and protein "factors"
E) sources of energy, including ATP
Answer: A
Topic: 10.11, 10.12
Skill: Conceptual Understanding
35) Which of the following statements about ribosomes is false?
A) A ribosome consists of two subunits.
B) Subunits of RNA are made of proteins and ribosomal RNA.
C) The ribosomes of prokaryotes and eukaryotes are the same in structure and function.
D) Each ribosome has two binding sites for tRNA.
E) Ribosomes coordinate the functioning of mRNA and tRNA.
Answer: C
Topic: 10.12
Skill: Factual Recall
36) Which of the following statements is false?
A) Translation consists of initiation, elongation, and termination.
B) During polypeptide initiation, an mRNA, the first amino acid attached to its tRNA, and the two subunits of a ribosome
are brought together.
C) An mRNA molecule transcribed from DNA is shorter than the genetic message it carries.
D) During the first step of initiation, an mRNA molecule binds to a small ribosomal subunit.
E) During the second step of initiation, a large ribosomal subunit binds to a small ribosomal subunit.
Answer: C
Topic: 10.13
Skill: Factual Recall
37) Which of the following options most accurately lists the sequence of events in translation?
A) codon recognition → translocation → peptide bond formation → termination
B) peptide bond formation → codon recognition → translocation → termination
C) codon recognition → peptide bond formation → translocation → termination
D) codon recognition → peptide bond formation → termination → translocation
E) peptide bond formation → translocation → codon recognition → termination
Answer: C
Topic: 10.14
Skill: Conceptual Understanding
38) Which of the following statements regarding the flow of genetic information is false?
A) Polypeptides form proteins that determine the appearance and function of the cell and organis m.
B) Eukaryotic mRNA is processed in several ways before export out of the nucleus.
C) The codons in a gene specify the amino acid sequence of a polypeptide.
D) Transcription occurs in the cytoplasm of eukaryotic cells.
E) Ribosomes function as factories that coordinate the functioning of mRNA and tRNA.
Answer: D
Topic: 10.15
Skill: Conceptual Understanding
39) Any change in the nucleotide sequence of DNA is called
A) a mutation.
B) an advantage.
C) a codon.
D) a translation.
E) an anticodon.
Answer: A
Topic: 10.16
Skill: Factual Recall
40) Consider the following sentence: "The dog did not eat." Which of the following variations of this sentence is most like
a base substitution mutation?
A) The dog did not et.
B) The dog dog did not eat.
C) The did dog not eat.
D) The doe did not eat.
E) The dog did not.
Answer: D
Topic: 10.16
Skill: Application
41) Consider the following sentence: "The dog did not eat." Which of the following variations of this sentence is most like
a reading frame mutation?
A) The dog dog did not eat.
B) The did dog not eat.
C) The dod idn ote at.
D) The did not eat.
E) The dog did dog did not eat.
Answer: C
Topic: 10.16
Skill: Application
42) A physical or chemical agent that changes the nucleotide sequence of DNA is called a(n)
A) reverse transcriptase.
B) terminator.
C) transposon.
D) mutagen.
E) anticodon.
Answer: D
Topic: 10.16
Skill: Factual Recall
43) A protein shell enclosing a viral genome is known as a(n)
A) capsule.
B) envelope.
C) phage.
D) capsid.
E) prophage.
Answer: D
Topic: 10.17
Skill: Factual Recall
44) Which of the following features characterizes the lytic cycle of a viral infection?
A) The cycle typically ends when the host bacterium divides.
B) The cycle typically leads to the lysis of the host cell.
C) The viral DNA is inserted into a bacterial chromosome.
D) The virus reproduces outside of the host cell.
E) The viral genes typically remain inactive once they are inside the host cell.
Answer: B
Topic: 10.17
Skill: Conceptual Understanding
45) Which of the following statements is false?
A) Some prophage genes can cause the transformation of a nonpathogenic bacterium into a form that causes human
disease.
B) Sometimes an environmental signal can trigger a switchover from the lysogenic to the lytic cycle.
C) The lysogenic cycle always occurs inside of host cells.
D) The lysogenic cycle typically results in the rapid lysis of all infected cells.
E) During a lysogenic cycle, viral DNA replication typically occurs without destroying the host cell.
Answer: D
Topic: 10.17
Skill: Conceptual Understanding
46) Viral DNA incorporated into host cell DNA is known as a(n)
A) capsid.
B) prophage.
C) envelope.
D) phage.
E) genome.
Answer: B
Topic: 10.17
Skill: Factual Recall
47) The envelope of a flu virus
A) helps the virus enter the cell.
B) is coded by viral genes.
C) helps the virus insert its DNA into the host cell genome.
D) changes rapidly, thereby helping the virus evade an immune system response.
E) accounts for viral resistance to antibiotics.
Answer: A
Topic: 10.18
Skill: Conceptual Understanding
48) Which of the following statements about herpesviruses is false?
A) Herpesviruses reproduce inside the host cell's mitochondria.
B) Herpesviruses acquire their envelopes from the host cell nuclear membrane.
C) Herpesviruses are DNA viruses.
D) Herpesviruses may remain latent for long periods of time while inside the host cell nucleus.
E) Herpesviruses may cause cold sores or genital sores to appear during times of physical or emotional stress. Answer: A
Topic: 10.18
Skill: Factual Recall
49) Which of the following statements about plant viruses is false?
A) Once in a plant, a virus can spread from cell to cell through plasmodesmata.
B) The genetic material in most plant viruses is RNA.
C) Preventing infections and breeding resistant plants can control viral infection in plants.
D) To infect a plant, a virus must first get past the plant's epidermis.
E) There are many successful ways to rid infected plants of a virus.
Answer: E
Topic: 10.18
Skill: Factual Recall
50) Which of the following statements regarding viral diseases is false?
A) RNA viruses tend to have an unusually high rate of mutation because their RNA genomes cannot be corrected by
proofreading.
B) New viral diseases often emerge when a virus infects a new host species.
C) Very few new human diseases have originated in other animals because the genetic differences are too great.
D) Some new viral diseases arise as a result of a mutation of existing viruses.
E) AIDS was around for decades before becoming a widespread epidemic.
Answer: C
Topic: 10.19-Evolution Connection
Skill: Factual Recall
51) What will be the most likely cause of a new avian flu pandemic like the 1918-1919 flu pandemic that killed approximately 40 million people worldwide?
A) sexual promiscuity
B) intravenous drug use and abuse
C) easy viral transmission from person to person
D) blood transfusions with tainted blood
E) increased international travel at affordable rates
Answer: C
Topic: 10.19-Evolution Connection
Skill: Application
52) What kind of virus is HIV?
A) a herpesvirus
B) a paramyxovirus
C) a retrovirus
D) a complex virus
E) a provirus
Answer: C
Topic: 10.20
Skill: Factual Recall
53) Which of the following enzymes does HIV use to synthesize DNA on an RNA template?
A) ligase
B) RNA polymerase
C) terminator enzyme
D) reverse transcriptase
E) DNA convertase
Answer: D
Topic: 10.20
Skill: Factual Recall
54) HIV does the greatest damage to
A) the adrenal glands.
B) pancreatic cells.
C) nervous tissue.
D) gametes.
E) white blood cells.
Answer: E
Topic: 10.20
Skill: Factual Recall
55) How do viroids harm the plants that are infected with them?
A) by increasing the plants' metabolic rate
B) by altering the plants' growth
C) by reducing the plants' seed production
D) by preventing leaf production
E) by destroying the root system
Answer: B
Topic: 10.21
Skill: Factual Recall
56) Which of the following statements about the treatment or prevention for a prion infection is true?
A) Antibiotic therapies such as penicillin are very effective cures.
B) High doses of anti-inflammatory drugs such as ibuprofen reduce the symptoms of prion infections.
C) Corticosteroid therapy is the only drug therapy that can reverse the effects of a prion infection.
D) Preventative vaccines have recently been shown to be effective in preventing prion infections.
E) There is no known treatment or cure for prion infections.
Answer: E
Topic: 10.21
Skill: Factual Recall
57) In the 1920s, Frederick Griffith conducted an experiment in which he mixed the dead cells of a bacterial strain that can cause pneumonia with live cells of a bacterial strain that cannot. When he cultured the live cells, some of the daught er colonies proved able to cause pneumonia. Which of the following processes of bacterial DNA transfer does this experiment demonstrate?
A) transduction
B) conjugation
C) transformation
D) transposition
E) crossing over
Answer: C
Topic: 10.22
Skill: Application
58) Transduction
A) is the direct transfer of DNA from one bacterium to another.
B) occurs when a bacterium acquires DNA from the surrounding environment.
C) is the result of crossing over.
D) occurs when a phage transfers bacterial DNA from one bacterium to another.
E) requires DNA polymerase.
Answer: D
Topic: 10.22
Skill: Factual Recall
59) Conjugation
A) is the direct transfer of DNA from one bacterium to another.
B) occurs when a bacterium acquires DNA from the surrounding environment.
C) is the result of crossing over.
D) occurs when a phage transfers bacterial DNA from one bacterium t o another.
E) requires DNA polymerase.
Answer: A
Topic: 10.22
Skill: Factual Recall
60) Conjugation, transformation, and transduction are all ways that bacteria
A) reduce their DNA content.
B) increase the amount of RNA in the cytoplasm.
C) change their ribosomes to eukaryotic ribosomes.
D) increase their genetic diversity.
E) alter their oxygen requirements.
Answer: D
Topic: 10.22
Skill: Conceptual Understanding
61) A friend accidentally sends an email to you that contains a comput er virus from his computer. Without knowing it, you infect your computer with the virus when you open the email. This process of spreading the computer virus using
emails is most like which of the following processes?
A) binary fission
B) conjugation
C) transduction
D) transformation
E) mitosis
Answer: C
Topic: 10.22
Skill: Application
62) When a bacterial cell with a chromosome-borne F factor conjugates with another bacterium, how is the transmitted donor DNA incorporated into the recipient's genome?
A) It is substituted for the equivalent portion of the recipient's chromosome by the process of crossing over.
B) It circularizes and becomes one of the recipient cell's plasmids.
C) The genes on the donor DNA of which the recipient does not have a copy are added to the recipient chromosome; the
remainder of the donor DNA is degraded.
D) The DNA of the recipient cell replicates, and the donor DNA is added to the end of the recipient DNA.
E) The donor and recipient DNA are both chopped into segments by restriction enzymes, and a new, composite
chromosome is assembled from the fragments.
Answer: A
Topic: 10.23
Skill: Factual Recall
63) In many bacteria, genes that confer resistance to antibiotics are carried on
A) factors.
B) R plasmids.
C) dissimilation plasmids.
D) transposons.
E) exons.
Answer: B
Topic: 10.23
Skill: Factual Recall
64) Conjugation between a bacterium that lacks an F factor (F-) and a bacterium that has an F factor on its chromosome (F+) would typically produce which of the following results?
A) The F-bacterium ends up carrying one or more plasmids from the F+ bacterium; the F+ bacterium is unchanged.
B) The F+ bacterium ends up with a recombinant chromosome that carries some genes from the F-bacterium, and the F-
bacterium ends up with an unaltered chromosome.
C) The F+ bacterium ends up with a recombinant chromosome that carries some genes from the F-bacterium, and the F-
bacterium ends up with a chromosome that lacks those genes.
D) The F-bacterium ends up with a recombinant chromosome that carries some genes from the F+ bacterium, and the F+
bacterium ends up with an unaltered chromosome.
E) The F-bacterium ends up with a recombinant chromosome that carries some genes from the F+ bacterium, and the F+
bacterium ends up with a chromosome that lacks those genes.
Answer: D
Topic: 10.23
Skill: Application
65) A functional F factor that is an R plasmid must contain all of the following elements except
A) genes for making sex pili.
B) genes for making the enzymes needed for conjugation.
C) a site for making the proteins needed for conjugation.
D) a site where DNA replication can begin.
E) genes for enzymes that confer resistance to antibiotics.
Answer: C
Topic: 10.23
Skill: Conceptual Understanding
66) Which of the following human activities has contributed to an increase in the number of bacteria having R plasmids?
A) nitrogen fixation by genetically engineered plants
B) widespread use of childhood vaccination in developing countries
C) improper use of restriction enzymes in research and medical facilities
D) increased carcinogen exposure from excessive fossil fuel burning
E) heavy use of antibiotics in medicine and in agriculture
Answer: E
Topic: 10.23
Skill: Conceptual Understanding
Art Questions
1)
What nucleotide sequence would be found on the partner DNA strand of the strand shown?
A) ACTGT
B) UGAGA
C) TGACA
D) TGUGU
E) TGTCA
Answer: C
Topic: 10.2, 10.3
Skill: Application
2)
How many origins of replication and how many replication forks are shown?
A) 3 origins and 3 replication forks
B) 3 origins and 6 replication forks
C) 6 origins and 3 replication forks
D) 6 origins and 6 replication forks
E) 6 origins and 12 replication forks
Answer: B
Topic: 10.5
Skill: Application
Scenario Questions
After reading the following paragraph, answer the question(s) below.
Exposure to the HIV virus doesn't necessarily mean that a person will develop AIDS. Some people h ave genetic resistance to infection by HIV. Dr. Stephen O'Brien from the U.S. National Cancer Institute has recently identified a mutant form of a gene, called CCR5, that can protect against HIV infection. The mutation probably originated in Europe among s urvivors of the bubonic plague. The mutated gene prevents the plague bacteria from attaching to cell membranes and, therefore, from entering and infecting body cells.
Although the HIV virus is very different from the bacteria that causes the plague, both diseases affect the exact same cells and use the same method of infection. The presence of the mutated gene in descendants of plague survivors helps prevent them from contracting AIDS. Pharmaceutical companies are using this information as the basis for a new approach to AIDS prevention. This would be very important in areas of the world where the mutation is scarce or absent, such as Africa.
1) The most likely method by which the mutated CCR5 gene prevents AIDS is by
A) covering the cell membrane.
B) rupturing the nuclear membrane.
C) attacking and destroying the HIV virus particles.
D) blocking transfer RNA from reaching the viral ribosomes.
E) coding for a protective protein in the cell membrane.
Answer: E
Topic: Opening Essay, 10.16, 10.19
Skill: Application
2) Which of the following shows the steps of a viral infection in the proper order?
A) virus locates host cell → enters nucleus → alters host cell DNA → destroys cell membrane
B) virus locates host cell → alters host cell DNA → host cell produces copies of virus → copies enter host cell nucleus →
nucleus leaves cell
C) virus kills host cell → enters nucleus → replaces all host DNA → releases copies of virus
D) virus locates host cell → penetrates cell membrane → enters nucleus → alters host cell DNA → host cell produces
copies of virus
E) virus locates host cell → forms hydrogen bonds → changes DNA to RNA→ host cell produces copies of virus Answer: D
Topic: Opening Essay, 10.16, 10.17
Skill: Factual Recall