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Life: The Science of Biology, Ninth Edition
Sadava • Hillis • Heller • Berenbaum
Chapter 15: Gene Mutation and Molecular Medicine
TEST FILE QUESTIONS
(By Catherine Ueckert)
Multiple Choice
1. Mutations are
a. heritable changes in the sequence of DNA bases that produce an observable phenotype.
b. changes in the nucleotide sequence of DNA that is passed on from one organism to
another.
c. mistakes in the incorporation of amino acids into proteins.
d. heritable changes in the mRNA of an organism.
e. None of the above
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 317
Bloom’s Category: 2. Understanding
2. Somatic and germ line are two types of mutations found in multicellular organisms.
Which of the following is a true statement regarding these two types of mutations?
a. Somatic mutations occur during sex cell formation.
b. Germ line mutations occur during mitosis.
c. Somatic mutations are passed on to sexually produced offspring.
d. An example of a germ line mutation is hemophilia.
e. All of the above
Answer: d
Textbook Reference: 15.1 What Are Mutations?
Page: 317
Bloom’s Category: 2. Understanding
3. In sickle-cell disease, one amino acid is substituted for another. This type of mutation
is referred to as a _______ mutation.
a. nonsense
b. missense
c. frame-shift
d. temperature sensitive
e. silent
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 318
Bloom’s Category: 1. Remembering
4. Silent mutations have no effect on amino acid sequences. This is due to the fact that
a. silent mutations are usually found in noncoding regions of DNA.
b. the genetic code is ambiguous.
c. silent mutations are recessive, and the presence of the dominant allele will result in a
functional protein.
d. silent mutations are conditional mutagens, and their phenotypes are only altered under
very restrictive conditions.
e. only a single base is involved in a series of thousands of nucleotides.
Answer: a
Textbook Reference: 15.1 What Are Mutations?
Page: 318
Bloom’s Category: 2. Understanding
5. The type of mutation that involves the insertion or a deletion of a single base in the
coding region of proteins is called
a. a missense mutation.
b. a nonsense mutation.
c. a point mutation.
d. an aberration.
e. None of the above
Answer: c
Textbook Reference: 15.1 What Are Mutations?
Page: 318
Bloom’s Category: 1. Remembering
6. People with sickle-cell disease have _______ abnormality.
a. a phenylalanine hydrolyase
b. an oncogene
c. a cholesterol transport
d. a hemoglobin
e. None of the above
Answer: d
Textbook Reference: 15.1 What Are Mutations?
Page: 318
Bloom’s Category: 1. Remembering
7. _______ is caused by a single base substitution that changes one amino acid in a
polypeptide. Individuals who are homozygous for this disease have defective, misshapen
red blood cells.
a. Duchenne muscular dystrophy
b. Sickle-cell anemia
c. Kuru
d. Cystic fibrosis
e. Familial hypercholesterolemia
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 318
Bloom’s Category: 1. Remembering
8. Single base changes in the coding regions of proteins can cause
a. missense mutations.
b. nonsense mutations.
c. frame-shift mutations.
d. silent mutations.
e. All of the above
Answer: e
Textbook Reference: 15.1 What Are Mutations?
Page: 318–319
Bloom’s Category: 2. Understanding
9. An example of a gain of function missense mutation is a mutation of the TP53 gene.
Normally, this protein inhibits cell division, but certain mutations in the TP53 gene
a. result in a gain of an oncogenic (cancer-causing) function.
b. do not result in a change in the amino acid sequence.
c. cause the protein to stop translation and no protein is made at all.
d. cause thymine to form covalent bonds with adjacent bases.
e. result in nondisjunction.
Answer: a
Textbook Reference: 15.1 What Are Mutations?
Page: 319
Bloom’s Category: 2. Understanding
10. Breaking and rejoining of chromosomes can lead to
a. deletions.
b. duplications.
c. inversions.
d. translocations.
e. All of the above
Answer: e
Textbook Reference: 15.1 What Are Mutations?
Page: 320
Bloom’s Category: 2. Understanding
11. The type of mutation that stops translation of a protein results in a shortened protein
because translation does not proceed beyond the mutation. An example is thalassemia,
which is
a. a missense mutation.
b. a nonsense mutation.
c. a frame-shift mutation.
d. an aberration.
e. None of the above
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 320
Bloom’s Category: 1. Remembering
12. Duplications and translocations differ in that
a. translocations involve the loss of a chromosomal segment, whereas duplications
involve addition of an entire chromosome.
b. duplications involve the breakage and swapping of DNA segments on homologous
chromosomes, whereas translocations are reciprocal exchanges on nonhomologous
chromosomes.
c. translocations involve the breakage and insertion of DNA segments in reverse order,
whereas duplications are the breakage at different points on the chromosome.
d. duplications lead to duplications of the chromosome, whereas translocations involve
swapping of chromosome segments.
e. translocations result in loss of chromosomal segments, whereas duplications result in
significant additions to nonhomologous chromosomes.
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 320
Bloom’s Category: 2. Understanding
13. Spontaneous mutations may be caused by all of the following except
a. a base, in its tautomer form, pairing incorrectly.
b. deamination, causing mismatched base pairs.
c. DNA polymerase making errors in base pairings.
d. free radicals changing the base structure so it is unrecognizable by DNA polymerase.
e. an occurence of nondisjunction.
Answer: d
Textbook Reference: 15.1 What Are Mutations?
Page: 321
Bloom’s Category: 2. Understanding
14. Benzopyrene, a component of cigarette smoke, can induce DNA mutations by
a. converting cytosine to uracil by deamination.
b. converting an amino group on cytosine into a keto group.
c. adding a chemical to guanine, making it unavailable for base pairing.
d. changing bases to forms unrecognizable by DNA polymerase.
e. breaking the sugar–phosphate backbone of DNA.
Answer: c
Textbook Reference: 15.1 What Are Mutations?
Page: 321
Bloom’s Category: 1. Remembering
15. Damage to DNA can be caused by _______ absorbed by thymine in DNA, causing
interbase covalent bonds.
a. X rays
b. cosmic radiation
c. ultraviolet radiation
d. smoke
e. cigarettes
Answer: c
Textbook Reference: 15.1 What Are Mutations?
Page: 321–322
Bloom’s Category: 2. Understanding
16. Mutational “hot spots” often occur when a methyl group has been added to
a. adenine.
b. cytosine.
c. guanine.
d. thymine.
e. uracil.
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 322
Bloom’s Category: 1. Remembering
17. Among the human genome’s 2.3 billion base pairs, there are about 16,000 DNAdamaging events daily. About what percentage is repaired?
a. 10 percent
b. 25 percent
c. 50 percent
d. 60 percent
e. 80 percent
Answer: e
Textbook Reference: 15.1 What Are Mutations?
Page: 322
Bloom’s Category: 1. Remembering
18. Nitrites, a human-made preservative for meats, and aflatoxin, a natural product
produced by the mold Aspergillus, are similar in that
a. they are converted by the endoplasmic reticulum into a mutagenic substance.
b. they readily lose an amine group to form a unique nitrogenous base.
c. their unmethylated cytosine loses its amino group to form uracil.
d. their thymine bases form covalent bonds with adjacent bases.
e. ultraviolet light distorts their DNA double helix, which interferes with translation.
Answer: a
Textbook Reference: 15.1 What Are Mutations?
Page: 322
Bloom’s Category: 4. Analyzing
19. The rates of DNA mutations are _______ in different organisms.
a. the same
b. constant
c. different
d. dependent on health
e. dependent on temperature
Answer: c
Textbook Reference: 15.1 What Are Mutations?
Page: 322
Bloom’s Category: 2. Understanding
20. Which of the following enzymes are used by bacteria to defend themselves against
bacteriophage?
a. DNA polymerase
b. Reverse transcriptase
c. Phosphofructokinase
d. Restriction endonuclease
e. None of the above
Answer: d
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 323
Bloom’s Category: 1. Remembering
21. Most restriction sites are _______ base pairs long.
a. 1 or 2
b. 4 to 6
c. about 10
d. about 20
e. over 50
Answer: b
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 323
Bloom’s Category: 1. Remembering
22. Which of the following enzymes would a bacterium most likely use to prevent its
DNA from being chopped up by its own restriction enzymes?
a. DNA polymerase
b. Ligase
c. Lactase
d. Reverse transcriptase
e. Methylase
Answer: e
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 323
Bloom’s Category: 2. Understanding
23. Restriction enzymes cleave DNA at specific sequences by hydrolyzing
a. the 3´ hydroxyl of one nucleotide and the 5´ phosphate of the next one.
b. at the 1´ carbons to cleave the nitrogenous bases.
c. at the 2´ carbons to cleave hydroxyl groups.
d. two phosphodiester linkages on the same strand.
e. four phosphodiester linkages, two on each strand.
Answer: a
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 323
Bloom’s Category: 2. Understanding
24. Which of the following is true about restriction enzymes?
a. They cut at regular intervals, every 4,000 base pairs.
b. They prefer to cut at DNA that has been methylated.
c. EcoRI’s restriction site is a palindrome.
d. All of the above
e. None of the above
Answer: c
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 323–324
Bloom’s Category: 2. Understanding
25. Which of the following is a palindromic recognition sequence?
a. 5´. . . CAATAG . . . 3´
b. 5´. . . CAATTG . . . 3´
c. 5´. . . CATTTG . . . 3´
d. 5´. . . GATTTC . . . 3´
e. 5´. . . CATCAT . . . 3´
Answer: b
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 324
Bloom’s Category: 3. Applying
26. DNA, because it has a _______ charge, moves to the _______ end of the field in gel
electrophoresis; _______ DNA molecules migrate the most quickly.
a. positive; positive; smaller
b. positive; positive; larger
c. positive; negative; smaller
d. negative; positive; larger
e. negative; positive; smaller
Answer: e
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 324
Bloom’s Category: 2. Understanding
27. A single hair is found at the scene of a crime. Which technology would you use first
to determine if the hair could have come from a certain suspect?
a. PCR
b. DNA sequencing
c. Fragment cloning
d. Probing
e. Antisense RNA
Answer: a
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 324
Bloom’s Category: 2. Understanding
28 DNA is _______ charged due to the presence of a _______ group.
a. negatively; methyl
b. negatively; phosphate
c. negatively; carbon
d. positively; methyl
e. positively; phosphate
Answer: b
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 324
Bloom’s Category: 1. Remembering
29. Electrophoresis separates DNA fragments of different sizes, but this technique does
not indicate which of the fragments contains the DNA piece of interest. This problem is
solved by
a. measuring the sizes of the bands on the gel.
b. removing the bands from the gel and hybridizing them with a known strand of DNA
complementary to the gene of interest.
c. knowing the isoelectric points of the piece in question.
d. identifying the molecular weights of the fragments in question.
e. None of the above
Answer: b
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 324–325
Bloom’s Category: 2. Understanding
30. Which of the following types of variations would be most detectable by gel
electrophoresis if the differences in the DNA were between two recognition sites for a
restriction enzyme?
a. SNPs
b. PCRs
c. HMRs
d. STRs
e. HMOs
Answer: d
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 324–325
Bloom’s Category: 2. Understanding
31. Which of the following statements is true regarding short tandem repeats (STRs)?
a. STRs are short, repetitive DNA sequences.
b. STRs occur side by side on chromosomes.
c. STRs usually occur in noncoding regions.
d. STRs contain 1–5 base pairs.
e. All of the above
Answer: e
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 325
Bloom’s Category: 2. Understanding
32. Which of the following types of variation involves changes at a single nucleotide
base?
a. SNPs
b. PCRs
c. HMRs
d. STRs
e. HMOs
Answer: a
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 325
Bloom’s Category: 1. Remembering
33. Which two methods are most often used in DNA fingerprinting?
a. Homologous and antisense RNA recombination
b. Pharming and phishing
c. Restriction digestion and gel electrophoresis
d. Gel electrophoresis and creation of expression vectors
e. Homologous recombination and the construction of gene libraries
Answer: c
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 325
Bloom’s Category: 1. Remembering
34. Which of the following statements about DNA fingerprinting is true?
a. To date, DNA fingerprinting has been used forensically to prove guilt more often than
it has been used to prove innocence.
b. DNA fingerprinting cannot be used on skeletons over 50 years old.
c. DNA fingerprinting examines just a small fraction of the genome.
d. All of the above
e. None of the above
Answer: c
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 325–326
Bloom’s Category: 2. Understanding
35. Which of the following statements regarding short tandem repeats (STRs) is false?
a. STRs are inherited.
b. STRs are the result of a single nucleotide base mutation.
c. The FBI uses 13 STR loci in its CODIS database to solve crimes.
d. STRs were used to confirm the execution of Tsar Nicholas II and his family.
e. DNA fingerprinting usually involves STR analysis.
Answer: b
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 325–326
Bloom’s Category: 2. Understanding
36. Paul Hebert proposed using cytochrome oxidase in the DNA barcode project because
it
a. evolves slowly.
b. mutates readily.
c. is found in most organisms.
d. Both a and c
e. Both b and c
Answer: e
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 326–327
Bloom’s Category: 2. Understanding
37. The DNA barcode project has the potential to
a. track species diversity in important ecological areas.
b. advance research in evolutionary biology.
c. detect undesirable microbes in food.
d. All of the above
e. None of the above
Answer: d
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 326–327
Bloom’s Category: 2. Understanding
38. Genetic mutations are often expressed phenotypically as
a. dysfunctional enzymes.
b. abnormal receptor proteins.
c. abnormal transport proteins.
d. abnormal structural proteins.
e. All of the above
Answer: e
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 327
Bloom’s Category: 2. Understanding
39. Individuals with PKU have an abnormal
a. lipoprotein.
b. prion.
c. triplet repeat.
d. oncogene.
e. enzyme.
Answer: e
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 327
Bloom’s Category: 1. Remembering
40. People with PKU often have too much of the amino acid _______ and too little of the
amino acid _______.
a. phenylalanine; alanine
b. phenylalanine; tyrosine
c. tyrosine; phenylalanine
d. tyrosine; alanine
e. alanine; tyrosine
Answer: b
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 327
Bloom’s Category: 2. Understanding
41. The primary consequence of untreated phenylketonuria is
a. muscle atrophy.
b. kidney failure.
c. mental retardation.
d. skeletal problems.
e. None of the above
Answer: c
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 328
Bloom’s Category: 1. Remembering
42. What is the most likely explanation for the light skin and hair of people with PKU?
a. Too much phenylalanine interferes with the production of melanin.
b. Their expression levels of the genes that produce melanin are low.
c. They cannot adequately synthesize tyrosine, an important precursor of melanin.
d. Melanin is broken down by excess phenylalanine.
e. Phenylalanine interferes with the transport of melanin to the appropriate location.
Answer: c
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 328
Bloom’s Category: 2. Understanding
43. People with sickle-cell disease have a(n) _______ abnormality.
a. phenylalanine hydrolyase
b. oncogene
c. cholesterol transport
d. hemoglobin
e. None of the above
Answer: d
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 328
Bloom’s Category: 1. Remembering
44. Sickle-cell disease is an inherited disease caused by an alteration of a single amino
acid in a protein. Specifically,
a. the sixth amino acid, glutamic acid, is replaced by valine.
b. the sixth amino acid, glutamic acid, is replaced by lysine.
c. the charge of the protein is changed, which causes the protein to change shape.
d. Both a and c
e. Both b and c
Answer: d
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 328
Bloom’s Category: 2. Understanding
45. Which of the following diseases results from an improperly functioning receptor
protein?
a. Sickle-cell anemia
b. PKU
c. Hemophilia
d. BSE
e. Familial hypercholesterolemia
Answer: e
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 328–329
Bloom’s Category: 4. Analyzing
46. Which of the following statements about prion diseases is true?
a. They are caused by viruses.
b. They cannot be transmitted between different species.
c. An abnormal protein can infect and cause disease by altering the normal structure of a
protein, causing the normal protein to assume an abnormal three-dimensional structure.
d. The disease almost always manifests itself within weeks of infection.
e. They are not found in humans.
Answer: c
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 329
Bloom’s Category: 2. Understanding
47. Stanley Prusiner received a Nobel Prize for
a. showing that some oncogenes are transcription factors.
b. purifying the protein responsible for TSEs and showing that no nucleic acids were
involved in the infectiousness of prion diseases.
c. discovering the protein responsible for cystic fibrosis.
d. sequencing the human genome with shotgun sequencing.
e. demonstrating that expanding triplet repeats are responsible for some diseases.
Answer: b
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 329
Bloom’s Category: 2. Understanding
48. “Mad cow disease” is most likely due to
a. an alteration in protein conformation.
b. a change in the amino acid sequences of a protein.
c. a missing protein.
d. the number of triplet repeats of a protein.
e. Both a and b
Answer: a
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 329
Bloom’s Category: 4. Analyzing
49. The molecular basis of which of the following human diseases is most similar to
“mad cow disease”?
a. Sickle-cell anemia
b. Huntington’s disease
c. Duchenne muscular dystrophy
d. Alzheimer’s disease
e. Fragile-X syndrome
Answer: d
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 329–330
Bloom’s Category: 1. Remembering
50. An RFLP
a. is a restriction fragment length polymorphism.
b. is inherited in a Mendelian fashion.
c. can be used as a genetic marker.
d. can be useful to help define a discrete gene.
e. All of the above
Answer: e
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 331
Bloom’s Category: 2. Understanding
51. Genetic markers must be polymorphic. Why is polymorphism an important
characteristic of genetic markers?
a. The various phenotypes help to identify the actual gene responsible for a genetic
disease.
b. Polymorphisms provide biochemical and physiological information about the disease.
c. Knowledge of the gene sequence allows for identification of the protein.
d. Radioactive labels can be added for easy identification of the disease.
e. They can be easily visualized as bands on an electrophoresis gel.
Answer: a
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 331
Bloom’s Category: 2. Understanding
52. Which of the following statements about fragile-X syndrome is true?
a. It affects more women than men.
b. Nearly all people with the fragile-X chromosomal abnormality are mentally retarded.
c. Individuals with more triplet repeats are less likely to get the disease.
d. In families with fragile-X syndrome, later generations tend to show more and more
severe symptoms of the disease.
e. None of the above
Answer: d
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333
Bloom’s Category: 2. Understanding
53. In fragile-X syndrome, males are said to be _______; grandchildren from their
daughters have _______ repeats than their daughters have.
a. imprinted; more
b. imprinted; fewer
c. premutated; more
d. premutated; fewer
e. multifactorial; more
Answer: c
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333
Bloom’s Category: 2. Understanding
54. Excess numbers of the CGG triplets in the FMR1 gene lead to clinical symptoms,
including mental retardation, because the
a. triplets bind to mRNAs of other genes.
b. cytosines in the repeats are more likely to be methylated, leading to inactivation of the
gene.
c. triplets cause genomic imprinting.
d. triplets make the gene so large that its mRNA cannot be transported properly.
e. triplets cause the protein to fold incorrectly.
Answer: b
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333
Bloom’s Category: 2. Understanding
55. Expanding repeats have been found in several diseases. How do expanding repeats
cause a disease?
a. All the codons are translated, causing a malfunctioning of the cell.
b. It increases methylation of the adenines, which stops transcription.
c. DNA polymerase is not able to properly attach to the promoter to start translation.
d. The repeats interfere with translation of normal mRNAs.
e. They cause a frame-shift mutation.
Answer: d
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333
Bloom’s Category: 2. Understanding
56. A genetic disease that is caused by a deletion in the X chromosome is
a. sickle-cell disease.
b. hemophilia.
c. Duchenne muscular dystrophy.
d. PKU.
e. Both a and b
Answer: c
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333
Bloom’s Category: 1. Remembering
57. The test developed in 1963 to screen newborns for PKU
a. involves positional cloning.
b. uses PCR and RFLPs to examine their DNA.
c. tests for the level of phenylalanine in their blood.
d. requires constructing a gene library.
e. None of the above
Answer: c
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 334
Bloom’s Category: 1. Remembering
58. Which of the following techniques relies on the same principle as RFLP?
a. Amniocentesis
b. Screening by allele-specific oligonucleotide hybridization
c. Screening by allele-specific cleavage
d. Guthrie’s test for PKU
e. Preimplantation screening
Answer: c
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 335
Bloom’s Category: 2. Understanding
59. Which of the following statements is true regarding allele-specific oligonucleotide
hybridization?
a. It uses oligonucleotide probes.
b. A minimum of a dozen bases is required.
c. The probe may be radioactive or fluorescent so hybridization can be easily detected.
d. It can reveal whether individuals are heterozygous.
e. All of the above
Answer: e
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 335–336
Bloom’s Category: 2. Understanding
60. Which of the following treatments involves restricting the substrate?
a. Use of statin drugs to reduce cholesterol
b. Giving children with PKU Lofenalac instead of formula
c. Chemotherapy treatment with 5-fluorouracil
d. Chemotherapy treatment with arabinocytosine
e. Chemotherapy treatment with Taxol
Answer: b
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 337
Bloom’s Category: 2. Understanding
61. Ingesting which of the following would be safest for a person with PKU?
a. Dietary products
b. Diet drinks with aspartame
c. Bread
d. Lofenalac
e. Fish
Answer: d
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 337
Bloom’s Category: 2. Understanding
62. In one type of cancer, myelogenous leukemia, certain white blood cells undergo a
gain-of-function mutation resulting in a totally new protein. The treatment involves
a. supplying the correct protein intravenously.
b. using molecular medicine to produce a drug to inactivate the protein.
c. using gene therapy to insert a new gene to supply the correct protein.
d. radiation and chemotherapy.
e. administrating large doses of adenosine deaminase.
Answer: b
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 338
Bloom’s Category: 2. Understanding
64. For gene therapy to be successful,
a. the new sequence of DNA must become part of the patient’s genome.
b. the gene must be precisely inserted into the patient’s cells.
c. the gene must be attached to a promoter that will express it.
d. Both a and b
e. a, b, and c
Answer: e
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 338–339
Bloom’s Category: 2. Understanding
Fill in the Blank
1. Although there are 6 billion base pairs of DNA packed in 46 human chromosomes,
only _______ percent of the DNA in the human genome codes for proteins.
Answer: 1.5
Textbook Reference: 15.0 Baby 81
Page: 316
Bloom’s Category: 1. Remembering
2. Mutations that exhibit the altered phenotype under certain restrictive conditions are
referred to as _______ mutations
Answer: conditional
Textbook Reference: 15.1 What Are Mutations?
Page: 318
Bloom’s Category: 1. Remembering
3. Silent mutations have no effect on amino acid sequences because they are usually
found in _______ regions of the DNA.
Answer: noncoding
Textbook Reference: 15.1 What Are Mutations?
Page: 318
Bloom’s Category: 2. Understanding
4. The TP53 gene normally functions to inhibit the cell cycle. If a gain of function
missense mutation occurs in the TP53 gene, the mutated TP53 gene will _______ (inhibit
or promote) the cell cycle.
Answer: promote
Textbook Reference: 15.1 What Are Mutations?
Page: 319
Bloom’s Category: 2. Understanding
5. Enzymes break the bonds of the DNA backbone between the 3´ hydroxyl group of one
nucleotide and the 5´ phosphate group of the next nucleotide. This process is called
_______.
Answer: restriction digestion
Textbook Reference: 15.1 What Are Mutations?
Page: 323
Bloom’s Category: 1. Remembering
6. Some bacteria use _______ enzymes as a defense mechanism; these enzymes cut up
foreign _______.
Answer: restriction; DNA
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 323
Bloom’s Category: 2. Understanding
7. The addition of _______ groups to their DNA is one method used by bacteria to
prevent their own DNA from being cut by restriction enzymes.
Answer: methyl
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 323
Bloom’s Category: 2. Understanding
8. Many restriction sites are _______; each strand contains the same sequence when read
from the 5´ end or the 3´ end.
Answer: palindromic
Textbook Reference: 15. 2 How Are DNA Molecules and Mutations Analyzed?
Page: 324
Bloom’s Category: 1. Remembering
9. A common method for sorting DNA by size is _______.
Answer: gel electrophoresis
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 324
Bloom’s Category: 1. Remembering
10. SNPs and STRs are two common markers used in _______.
Answer: DNA fingerprinting
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 325
Bloom’s Category: 2. Understanding
11. The DNA _______ project attempts to identify all organisms on Earth.
Answer: barcode
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 326
Bloom’s Category: 1. Remembering
12. Individuals with the disease PKU cannot break down the amino acid _______.
Answer: phenylalanine
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 327
Bloom’s Category: 1. Remembering
13. A change of glutamic acid to valine at the sixth position of the β-globin is responsible
for _______.
Answer: sickle-cell disease
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 328
Bloom’s Category: 1. Remembering
14. An abnormal protein that is able to infect and alter normal protein three-dimensional
structures is called a _______.
Answer: prion
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 329
Bloom’s Category: 1. Remembering
15. Most diseases that are genetic are _______; that is, they are caused by the interactions
of many genes as well as by environmental factors.
Answer: multifactorial
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 330
Bloom’s Category: 2. Understanding
16. Since the 1990s, researchers have isolated a mutated gene and then characterized the
protein. Because this process is opposite to the genetic analyses done before the mid1980s, it is called _______.
Answer: reverse genetics
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 330
Bloom’s Category: 1. Remembering
17. The reference points for gene isolation are called _______.
Answer: genetic markers
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 331
Bloom’s Category: 1. Remembering
18. In families with the fragile-X chromosomal abnormality, males with a moderate
number of triplet repeats are usually unaffected and are considered to be _______.
Answer: premutated
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333
Bloom’s Category: 2. Understanding
19. Fragile-X syndrome arises from an excessive number of triplet repeats of the
sequence _______.
Answer: CGG
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333
Bloom’s Category: 1. Remembering
20. Newborn screening tests are done for about 25 genetic diseases using the newborn
babies’ _______.
Answer: blood
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 334
Bloom’s Category: 2. Understanding
21. Amniocentesis is commonly used in prenatal screening for _______.
Answer: genetic abnormalities
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 335
Bloom’s Category: 1. Remembering
22. The screening technique that uses oligonucleotide probes to screen for genetic
diseases is _______.
Answer: allele-specific oligonucleotide hybridization
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 335
Bloom’s Category: 1. Remembering
23. The study of allele-specific cleavage differences detects genetic diseases by
examining patterns of activity of _______ enzymes.
Answer: restriction
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 335
Bloom’s Category: 2. Understanding
24. Knowledge of genes and the proteins they make is being used to design new drug
treatments for genetic diseases. This new field is called _______.
Answer: molecular medicine
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 337–338
Bloom’s Category: 1. Remembering
25. The goal of _______ is to insert a gene that will be expressed in the host.
Answer: gene therapy
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 338
Bloom’s Category: 2. Understanding
Diagram
1. Refer to the diagram below showing the RFLP patterns at a hypothetical locus in a
family wherein some individuals develop high cholesterol. Immediately below the RFLP
patterns are the cholesterol levels of each corresponding individual. What inferences can
we draw from these results?
Answer: There is a striking association between the RFLP pattern and the cholesterol
level of the individuals. Only those with the broadly-spaced RFLP pattern (from left,
lanes 2, 3, 5, 6, 8, 9, and 12) have cholesterol levels over 200.
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 331
Bloom’s Category: 5. Evaluating
STUDY GUIDE QUESTIONS
(By Nancy Guild)
Knowledge and Synthesis
1. Fragile-X syndrome is caused by
a. a single base change in the DNA.
b. the changing of a valine into a glutamic acid.
c. triplet expansion.
d. a chromosomal translocation.
e. nondisjunction of the X chromosome in meiosis.
Answer: c
Feedback: Fragile-X syndrome is caused by a triplet expansion on the X chromosome,
not a single base change, a translocation, or an alteration of protein sequence.
Nondisjunction of the X chromosome would result in XO, also known as Turner’s
syndrome.
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333
2. A nonfunctional membrane protein is responsible for
a. hemophilia.
b. sickle-cell disease.
c. Duchenne muscular dystrophy.
d. cystic fibrosis.
e. PKU.
Answer: d
Feedback: The chloride transporter is a membrane protein that, when nonfunctional,
causes cystic fibrosis. Hemophilia is caused by a defect in a clotting factor. Sickle-cell
disease is caused by a defect in β-globin. PKU is caused by a defect in an enzyme in a
biochemical pathway. Duchenne muscular dystrophy is caused by a defect in the muscle
protein dystrophin.
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 329
3. Expanding triplet repeats
a. occur during DNA replication due to slippage of DNA polymerase.
b. are caused by errors in DNA synthesis with reverse transcriptase.
c. can be identified using RFLP mapping.
d. occur in individuals with a normal number of triplet codons.
e. Both a and c
Answer: e
Feedback: Expanding triplet repeats are thought to be due to slippage of DNA
polymerase during DNA replication, and result in an increasing number of triplet repeats
in those cells. That increase in the DNA sequence can be distinguished from the DNA
sequence of a normal individual by means of RFLP analysis. Reverse transcriptase is an
enzyme from HIV that copies RNA into DNA.
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333–334
4. In sickle-cell disease,
a. a clotting factor in the blood is nonfunctional.
b. the sixth amino acid is changed from a valine to a glutamic acid.
c. the sixth amino acid is changed to a stop codon.
d. hemoglobin builds up in the red blood cells.
e. the structure of β-globin is altered, and the hemoglobin protein forms aggregates in the
red blood cells.
Answer: e
Feedback: In sickle-cell disease, the sixth amino acid is changed from a glutamic acid to
a valine (not from a valine to a glutamic acid, and not to a stop codon). The resulting
change causes the hemoglobin protein to form aggregates in the red blood cell. The
concentration of hemoglobin in the red blood cell is not altered in sickle-cell disease.
Textbook Reference: 15.1 What Are Mutations?
Page: 318
5. Metabolic disorders are
a. caused by mutations in centromeres.
b. the result of mutations in genes encoding enzymes that are required to synthesize
particular compounds in the cell (such as an amino acid).
c. due to abnormal membrane proteins that transport chloride ions.
d. caused by prions.
e. All of the above
Answer: b
Feedback: Some metabolic disorders are caused by mutations in genes that encode
enzymes in a biochemical pathway (such as the pathway for the synthesis of
phenylalanine). Mutations in centromeres and genes for chloride transporters do not
result in metabolic disorders. Prions are not the result of a mutation; they are the result of
the abnormal folding of a protein.
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 337
6. Prions
a. cause scrapie in sheep.
b. are caused by abnormally folded proteins that interfere with normal brain-cell function.
c. cause “mad cow” disease.
d. are transmitted through the ingestion of infected tissue.
e. All of the above
Answer: e
Feedback: Prions result from abnormally folded proteins that interfere with normal braincell function. “Mad cow” disease and scrapie are caused by prion formation. They are
thought to be passed from organism to organism by the eating of infected tissue.
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 329–330
7. Human genetic disease can be caused by
a. an autosomal recessive trait.
b. translocations.
c. a deletion in a chromosome.
d. a mutant allele that is dominant to the wild-type allele.
e. All of the above
Answer: e
Feedback: All these mutations and chromosome alterations can cause human disease.
Textbook Reference: 15.1 What Are Mutations?
Page: 320
8. Mutations that result in human disease include
a. expanding triplet repeats that occur during DNA synthesis.
b. point mutations that do not change the amino acid sequence of the gene.
c. prion diseases such as “mad cow” in humans.
d. mutations in restriction sites in the DNA.
e. Both a and d
Answer: e
Feedback: Expanding triplet repeats cause a variety of diseases, including fragile-X
syndrome, Huntington’s chorea, and myotonic dystrophy. Point mutations that do not
alter the amino acid sequence of a protein are silent mutations and do not cause disease.
Prion diseases are not the result of a mutation in a gene, but are due to the abnormal
folding of a particular protein. Mutations in a gene coding sequence or regulatory
sequence could alter a restriction site.
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Diseases?
Page: 333
9. Genetic screening
a. has been used to treat embryos carrying a mutant allele.
b. requires that gene sequences are the same in affected and unaffected individuals.
c. has been used to identify fathers who are carriers for X-linked alleles.
d. has been used to identify mutant alleles in embryos.
e. requires dissimilarity between the alleles being tested and those that are linked to a
particular disease.
Answer: c
Feedback: Genetic screening has been used to analyze in vitro fertilized embryos (at the
eight-cell stage) but cannot be used to treat those embryos. To be useful, the alleles being
tested have to be different in affected versus unaffected individuals, and the specific
alleles that are linked to a disease trait should be the same. Fathers are not carriers for Xlinked diseases; they express all their X-linked alleles.
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 334–337
10. For gene therapy to be most effective, genes should
a. be delivered to the germ-line cells using a viral vector.
b. be inserted into the host DNA chromosome at random sites.
c. be expressed in the host cells in response to the appropriate environmental signals.
d. be similar to the defective gene.
e. have antibiotic resistance markers.
Answer: c
Feedback: The most effective conditions for gene therapy are for genes to reside
permanently at the appropriate site in the host chromosome in the individual’s cells and
be expressed under the correct environmental signals. The gene should be identical to the
wild-type copy of the gene and does not require antibiotic resistance markers. Viral
delivery of the gene to germ-line cells will not affect the diseased somatic cells.
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 338
11. Allele-specific oligonucleotides
a. should be tightly linked to the disease allele.
b. can be used to induce spontaneous mutations.
c. can detect a change in a restriction endonuclease pattern.
d. are used to detect mutations in protein.
e. a, c, and d
Answer: e
Feedback: Allele-specific oligonucleotides can detect specific changes in the DNA,
including mutations, disease alleles, and changes in restriction sites. To be useful, they
should be tightly linked to the disease allele. They cannot induce spontaneous mutations.
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 335–336
12. Conditional mutations
a. are mutations that are expressed in wild-type cells.
b. are deletion mutations.
c. are analyzed under permissive and restrictive conditions.
d. produce gene products that are nonfunctional under all conditions.
e. can be analyzed only under restrictive conditions.
Answer: c
Feedback: Conditional mutations are used to compare gene expression under permissive
and restrictive conditions. Conditional mutations are not expressed in mutant cells under
restrictive conditions but are expressed under permissive conditions. Under restrictive
conditions they produce nonfunctional gene products. They cannot be deletions because
the gene product has to be functional at the permissive temperatures.
Textbook Reference: 15.1 What Are Mutations?
Page: 318
13. Gel electrophoresis
a. causes DNA to be pulled through the gel toward the negative end of the field.
b. causes larger DNA fragments to move more quickly through the gel than smaller DNA
fragments.
c. is used to identify and isolate DNA fragments.
d. is required for PCR reactions.
e. is used in allele-specific oligonucleotide hybridization.
Answer: c
Feedback: DNA fragments migrate toward the positive end of the electric field, with the
smallest fragments migrating the fastest. PCR reactions do not require gel
electrophoresis, although their products are analyzed by gel electrophoresis. Allelespecific oligonucleotide hybridization does not require gel electrophoresis.
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 324
14. Gain of function mutations
a. are dominant mutations that are expressed in wild-type cells.
b. are dominant mutations that are expressed in mutant cells.
c. are the cause of continuous division in cancer cells.
d. can be analyzed only under restrictive conditions.
e. are expressed only with the appropriate environmental signals.
Answer: b
Feedback: Gain of function mutations are dominant and are expressed in mutant cells.
They do not respond to the appropriate environmental signals and do not have a
restrictive condition under which they are expressed. Some gain of function mutations are
seen in cancer cells, but mutations in tumor suppressors are also responsible for
unregulated cell division in cancer cells.
Textbook Reference: 15.1 What Are Mutations?
Page: 318
15. Which of the following mutations would still allow protein X to be functional?
a. A missense mutation in the third codon of gene X
b. A silent mutation in the third codon of gene X
c. A deletion of the first three codons of gene X
d. A frame-shift mutation in the third codon of gene X
e. A nonsense mutation in the third codon of gene X
Answer: b
Feedback: A silent mutation (no change in the amino acid sequence) would result in no
change in protein function. All of the other mutations would alter the amino acid
sequence. A missense mutation would change the amino acid sequence at that codon and
could result in a nonfunctional protein. A deletion would remove the first three amino
acids of the protein. A frame shift would cause all of the codons after that mutation to be
out of frame. A nonsense mutation would terminate translation at that codon.
Textbook Reference: 15.1 What Are Mutations?
Page: 318–320
16. Which of the following chromosomal mutations would still allow protein X to be
functional?
a. Deletion of the last 100 codons of gene X
b. A duplication of gene X
c. An inversion of the last 100 codons of gene X
d. A translocation of the last 100 codons of gene X to another chromosome
e. None of the above
Answer: c
Feedback: A duplication of gene X might allow the protein to be functional. All of the
rest of these chromosomal mutations would remove large regions of the coding sequence
or would position part of that sequence in the opposite direction (inversion), which would
produce a nonfunctional protein X.
Textbook Reference: 15.1 What Are Mutations?
Page: 318–320
17. Which of the following mutations would probably be the most deleterious?
a. A missense mutation in the second codon
b. A frame-shift mutation in the second codon
c. A nonsense mutation in the last codon
d. A silent mutation in the second codon
e. A missense mutation in the last codon
Answer: b
Feedback: The mutation that is potentially the most dangerous is the frame shift in the
second codon. All of the other codons would be out of register and no functional protein
could be made. A missense mutation in the second codon could be disastrous or minimal,
depending on how crucial that second amino acid was to the folding and functioning of
the protein. A nonsense or missense mutation at the end of the coding sequence would
have less effect on protein function because almost every amino acid in the protein would
have been synthesized correctly. Again, this would depend on how important that last
codon was to the proper folding and functioning of the protein. A silent mutation would
have no effect on protein function because the amino acid inserted at that codon would be
the same.
Textbook Reference: 15.1 What Are Mutations?
Page: 317–320
Application
1. Phenylketonuria (PKU) and Duchenne muscular dystrophy (MD) are both molecular
diseases that are caused by mutations in particular genes, yet PKU is easier to treat than
MD. Why?
Answer: Phenylketonuria is a metabolic disease that results from a deficient enzyme,
phenylalanine hydroxylase. Patients with PKU can build up harmful levels of
phenylalanine in their systems and can be treated by restricting their intake of
phenylalanine. Muscular dystrophy is caused by a defect in a structural protein,
dystrophin, and results in dysfunctional muscle tissue. This structural dysfunction cannot
be reversed with the application of any drug.
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 337
2. Two individuals have a mutation in gene X but at different sites. The mutation affects
the first individual adversely, and the second individual experiences no effect. Explain
this observation.
Answer: The mutation in gene X in the first individual must have occurred in an essential
region of the gene that is required for its function. The mutation in gene X in the second
individual may be a silent mutation, or it may be in a region that is nonessential for the
function of that protein.
Textbook Reference: 15.1 What Are Mutations?
Page: 318–320
3. Bacterial restriction endonucleases provide a type or “immunity” to viral infections.
Describe how these endonucleases protect the bacterial cell from viral infections.
Answer: Restriction endonucleases will cut DNA at specific sites and can degrade the
viral DNA once it has infected the bacterial cell. Bacteria modify their own DNA so the
restriction endonucleases cannot cut their own DNA.
Textbook Reference: 15.1 What Are Mutations?
Page: 324–325
4. When a gene that has been mutated is expressed, the resulting protein may misfold and
be nonfunctional. How is a misfolded protein (due to a mutation) different from a
misfolded prion protein?
Answer: The misfolding of a prion protein is due to the presence of another misfolded
prion in its environment and not due to a mutation in the gene sequence that results in a
misfolded protein.
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 329–330
5. You have characterized over 100 mutations in a particular gene that are linked to a
certain disease. The mutations you have identified are all due to a single base change in
one codon of the gene encoding protein X. Which DNA technique would you use to
analyze patients who might have this disease?
Answer: Since all of the mutations you isolated occur in the same codon, you could use a
set of SNPs for that codon. SNPs identify single base changes in the DNA.
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 327–329
TEXTBOOK SELF-QUIZ
1. Phenylketonuria is an example of a genetic disease in which
a. a single enzyme is not functional.
b. inheritance is sex-linked.
c. two parents without the disease cannot have a child with the disease.
d. mental retardation always occurs, regardless of treatment.
e. a transport protein does not work properly.
Answer: a
2. Mutations of the gene for β-globin
a. are usually lethal.
b. occur only at amino acid position 6.
c. number in the hundreds.
d. always result in sickling of red blood cells.
e. can always be detected by gel electrophoresis.
Answer: c
3. Multifactorial (complex) diseases
a. are less common than single-gene diseases.
b. involve the interaction of many genes with the environment.
c. affect less than 1 percent of humans.
d. involve the interactions of several mRNAs.
e. are exemplified by sickle-cell disease.
Answer: b
4. In fragile-X syndrome,
a. females are affected more severely than males.
b. a short sequence of DNA is repeated many times to create the fragile site.
c. both the X and Y chromosomes tend to break when prepared for microscopy.
d. all people who carry the gene that causes the syndrome are mentally retarded.
e. the basic pattern of inheritance is autosomal dominant.
Answer: b
5. Most genetic diseases are rare because
a. each person is unlikely to be a carrier for harmful alleles.
b. genetic diseases are usually sex-linked and so uncommon in females.
c. genetic diseases are always dominant.
d. two parents probably do not carry the same recessive alleles.
e. mutation rates in humans are low.
Answer: d
6. Mutational “hot spots” in human DNA
a. always occur in genes that are transcribed.
b. are common at cytosines that have been modified to 5-methylcytosine.
c. involve long stretches of nucleotides.
d. occur only where there are long repeats.
e. are very rare in genes that code for proteins.
Answer: b
7. Newborn genetic screening for PKU
a. is very expensive.
b. detects phenylketones in urine.
c. has not led to the prevention of mental retardation resulting from this disorder.
d. should be done during the second or third day of an infant’s life.
e. uses bacterial growth to detect excess phenylketones in blood.
Answer: d
8. Genetic diagnosis by DNA testing
a. detects only mutant and not normal alleles.
b. can be done only on eggs or sperm.
c. involves hybridization to rRNA.
d. often utilizes restriction enzymes and a polymorphic site.
e. cannot be done with PCR.
Answer: d
9. Which of the following is not a way to treat a genetic disease?
a. Inhibiting a harmful biochemical reaction
b. Adding the wild-type allele to cells expressing the mutation
c. Restricting the substrate of a harmful biochemical reaction
d. Replacing a mutant allele with the wild-type allele in the fertilized egg
e. Supplying a wild-type protein that is missing due to mutation
Answer: d
10. Current treatments for genetic diseases include all of the following except
a. restricting a dietary substrate.
b. replacing the mutant gene in all cells.
c. alleviating the patient’s symptoms.
d. inhibiting a harmful metabolic reaction.
e. supplying a protein that is missing.
Answer: b
BIOPORTAL DIAGNOSTIC QUIZ (Personalized Study Plan Quiz)
(By Richard McCarty)
1. In multicellular organisms
a. somatic mutations are passed on to offspring produced by sexual reproduction.
b. somatic mutations may be passed to daughter cells by mitosis.
c. all mutations produce phenotypic changes.
d. meiosis is not required for the transmission of germ line mutations to the next
generation.
e. all mutations are point mutations.
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 317
Bloom’s Category: 2. Understanding
2. A point mutation
a. is a result of a chromosomal deletion.
b. is always silent.
c. does not occur in noncoding regions of DNA.
d. is a change in a single nucleotide of DNA.
e. is not transmitted to daughter cells.
Answer: d
Textbook Reference: 15.1 What Are Mutations?
Page: 318
Bloom’s Category: 1. Remembering
3. A mutant strain of yeast grew well at 20°C, but not at 37°C, whereas the wild-type
strain grew well at both temperatures. The mutation is an example of a
a. gain of function mutation.
b. conditional mutation.
c. missense mutation.
d. point mutation.
e. frame-shift mutation.
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 318–319
Bloom’s Category: 2. Understanding
4. A nonsense mutation
a. is a result of a change in a codon for an amino acid in a protein to a stop codon.
b. results in a shorter mRNA transcript of the gene.
c. results in a protein that is truncated from the N-terminal end.
d. would likely not affect the activity of a protein.
e. would not affect the primary structure of a protein.
Answer: a
Textbook Reference: 15.1 What Are Mutations?
Page: 319–320
Bloom’s Category: 3. Applying
5. Frame-shift mutations
a. result in a single amino acid substitution.
b. almost always lead to loss of function.
c. result from only single or double base deletions of a base(s).
d. cause the ribosome to misread mRNA.
e. result only from the addition of an extra base.
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 320
Bloom’s Category: 2. Understanding
6. Which of the following mutations is not a chromosomal mutation?
a. Large deletions
b. Inversions
c. Point mutations
d. Translocations
e. Duplications
Answer: c
Textbook Reference: 15.1 What Are Mutations?
Page: 320
Bloom’s Category: 2. Understanding
7. Mutations
a. are always deleterious.
b. can arise from errors in DNA replication.
c. are always caused by mutagens.
d. occur at the same rate for all bases.
e. are of no importance to evolution.
Answer: b
Textbook Reference: 15.1 What Are Mutations?
Page: 320–322
Bloom’s Category: 2. Understanding
8. Chemical mutagens should also be carcinogens. Some compounds that did not increase
the mutation rate of the bacterium E. coli are nonetheless potent carcinogens in animals.
Why?
a. The genetic code in the bacterium differs from that in animals.
b. Bacterial genes are often arranged in operons.
c. Some chemicals are not mutagenic or carcinogenic unless they are altered in the ER of
animal cells.
d. Many animal cell genes have introns.
e. Animals may have germ line mutations.
Answer: c
Textbook Reference: 15.1 What Are Mutations?
Page: 322
Bloom’s Category: 5. Evaluating
9. Restriction enzymes
a. cleave DNA at sequence-specific sites.
b. are called restriction enzymes because they restrict the range of viruses that can attack
a bacterial species.
c. do not cut the host bacterium’s DNA.
d. are essential tools in molecular biology.
e. All of the above
Answer: e
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 323–324
Bloom’s Category: 2. Understanding
10. Restriction enzymes
a. cut single-stranded DNA.
b. cut double-stranded DNA at any palindromic sequence.
c. cleave DNA to very small pieces.
d. cleave double-stranded DNA at specific palindromic sequences.
e. have been isolated from just a few species of microrganisms.
Answer: d
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 323–324
Bloom’s Category: 2. Understanding
11. In gel electrophoresis of DNA fragments,
a. the fragments migrate towards the cathode (negative charge).
b. the fragments are separated based on their charge differences.
c. the fragments are separated on the basis of their sizes.
d. the fragments migrate towards the anode (positive charge) because of the positive
charge of the bases.
e. large fragments migrate more quickly than small fragments.
Answer: c
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 324–325
Bloom’s Category: 2. Understanding
12. In DNA fingerprinting,
a. DNA is non-specifically cut by nucleases.
b. DNA is cut by nucleases into fragments of equal size.
c. DNA fragments are separated by gel electrophoresis based on their charge.
d. repetitive DNA sequences are often used,
e. PCR is not useful.
Answer: d
Textbook Reference: 15.2 How Are DNA Molecules and Mutations Analyzed?
Page: 325–326
Bloom’s Category: 1. Remembering
13. Which of the mutations below do you think would have the greatest effect on the
activity of the mutant enzymes?
a. Glutamate to lysine
b. Lysine to arginine
c. Glutamate to aspartate
d. Leucine to isoleucine
e. Serine to threonine.
Answer: b
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 327–329
Bloom’s Category: 4. Analyzing
14. Transmissible spongiform encephalopathies (TSEs) are
a. caused by a protein.
b. genetic diseases.
c. not transmissible to humans.
d. caused by RNA.
e. caused by viruses.
Answer: a
Textbook Reference: 15.3 How Do Defective Proteins Lead to Diseases?
Page: 329–330
Bloom’s Category: 2. Understanding
15. Restriction fragment banding patterns
a. are useful in constructing pedigrees.
b. show sex-linked inheritance.
c. are detected by RNA probes.
d. difficult to visualize on electrophoresis gels.
e. the same in most individuals.
Answer: a
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Disease?
Page: 331–332
Bloom’s Category: 1. Remembering
16. Fragile-X syndrome
a. is a result of a point mutation in the reading frame of the FMR1 gene.
b. is a result of a mutant form of the FMR1 protein.
c. is phenotypically evident in heterozygous females.
d. results from an increase in the number of repeated CGG triplets in the promoter region
of the FMR1 gene.
e. becomes less phenotypically evident in later generations.
Answer: d
Textbook Reference: 15.4 What DNA Changes Lead to Genetic Disease?
Page: 333–334
Bloom’s Category: 2. Understanding
17. Phenylketonuria
a. is not a genetic disorder.
b. is detected by analysis for phenylalanine in a blood sample.
c. is detected in newborns humans by DNA analysis.
d. results from a mutation in the promoter region of a gene.
e. causes mental retardation even if diagnosed soon after birth.
Answer: b
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 334
Bloom’s Category: 3. Understanding
18. DNA testing by allele-specific hybridization
a. cannot detect genetic abnormalities in heterozygotes.
b. requires non-specific oligonucleotide probes.
c. requires PCR to amplify the gene in question.
d. requires that the mutation of the gene in question be in a restriction site.
e. is less precise than RFLP analysis.
Answer: c
Textbook Reference: 15.5 How Is Genetic Screening Used to Detect Diseases?
Page: 335–336
Bloom’s Category: 2. Understanding
19. Treating genetic diseases
a. is successful for the majority of genetic diseases.
b. always includes gene replacement therapy.
c. works only for inherited diseases.
d. requires an understanding of how the disease works at the molecular level.
e. works only for diseases of somatic cells.
Answer: d
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 337–338
Bloom’s Category: 1. Remembering
20. Gene therapy requires
a. a way to introduce new genes into the patient’s cells.
b. the expression of the introduced gene in vivo.
c. insertion of the new gene into the host DNA.
d. identification and isolation of the wild type allele.
e. All of the above
Answer: e
Textbook Reference: 15.6 How Are Genetic Diseases Treated?
Page: 338–339
Bloom’s Category: 2. Understanding