Genetics From Genes To Genomes 6th Edition By Leland Hartwell – Test Bank

Chapter 11 Analyzing Genomic Variation

1) Given that an individual is a compound heterozygote at the CFTR locus, the gene that causes cystic fibrosis, what can be inferred?
A) If the individual has children, all the children will have cystic fibrosis.
B) At least one of the individual’s parents had cystic fibrosis.
C) The individual is a carrier for cystic fibrosis, but does not have the disease.
D) A drug that effectively treats one allele may not treat the other.

Answer: D
Section: 11.04
Topic: Positional Cloning
Learning Objective: 11.04.04 Discuss the consequences of allelic heterogeneity, compound heterozygosity, and locus heterogeneity.
Bloom’s: 3. Apply
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2) Most polymorphisms do not result in a phenotypic difference because they are typically
A) nonsense mutations.
B) either missense or neutral mutations.
C) either silent mutations or are in non-coding regions.
D) either missense mutations or are in promoter regions.

Answer: C
Section: 11.01
Topic: Variation Among Genomes
Learning Objective: 11.01.02 Explain why most of these DNA polymorphisms are not responsible for the phenotypic differences between people.
Bloom’s: 2. Understand
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3) Which statement about SNPs in the human genome is true?
A) Most SNPs have an effect on phenotype.
B) Any two human genome copies will have on average 3 million single nucleotide polymorphisms.
C) SNPs refer only to deletions or insertions, not base substitutions.
D) Most SNPs are located in the introns of genes, and thus effect phenotype.

Answer: B
Section: 11.01
Topic: Variation Among Genomes
Learning Objective: 11.01.01 Estimate how many DNA polymorphisms differentiate the genomes of any two people.
Bloom’s: 1. Remember
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4) Which is an example of a SNP? (Select all that apply.)
A) A single base near the neurofibromatosis gene can be a G or a T; phenotype is not affected.
B) A single base change in the gene for β globin changes an amino acid and results in sickle cell anemia.
C) Individuals with Huntington disease have more trinucleotide repeats in the coding region of the HD gene than normal individuals.
D) The most common cystic fibrosis allele has a deletion of three base pairs in the coding region of the CFTR gene.

Answer: A, B
Section: 11.03
Topic: Variation Among Genomes
Learning Objective: 11.01.03 Differentiate among different classes of DNA variants in terms of their structures, mechanisms of formation, and frequency in genomes.
Bloom’s: 2. Understand
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5) The most common mutant allele of the PAH gene, which is responsible for the metabolic disorder PKU, has a SNP in the splice donor site of one intron. What is the simplest way to detect this allele?
A) PCR using genomic DNA as template and two primers, one on either side of the SNP, followed by gel electrophoresis
B) PCR using genomic DNA as template and two primers, one complementary to the region containing the SNP, followed by gel electrophoresis
C) PCR using two primers, one on either side of the SNP, followed by sequencing the PCR products
D) Direct exome sequencing using a microarray
E) Whole-genome sequencing

Answer: C
Section: 11.02
Topic: Genotyping a Known Disease-Causing Mutation
Learning Objective: 11.02.02 Describe how the sequencing or sizing of PCR products can elucidate genotypes.
Bloom’s: 3. Apply
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6) Fragile X syndrome is caused by expansion of a trinucleotide repeat in the 5′ UTR of the FMR-1 gene. What is the simplest way to detect this expansion?
A) PCR using genomic DNA as template and two primers that are complementary to repeats on either side of the expansion, followed by gel electrophoresis
B) PCR using genomic DNA as template and two primers, one complementary to the repeat region and the other complementary to unique sequence, followed by gel electrophoresis
C) PCR using two primers that are complementary to unique sequences on either side of the repeat region, followed by sequencing the PCR products
D) Direct exome sequencing using a microarray
E) Whole-genome sequencing

7) Which does a successful PCR require?
A) at least 100 starting DNA template molecules
B) some sequence information about the region to be amplified
C) a cloned cDNA of the region to be amplified
D) a double-stranded DNA template of at least 100 kb to amplify
E) an undamaged DNA template with intact chromosomes

Answer: B
Section: 11.02
Topic: Genotyping a Known Disease-Causing Mutation
Learning Objective: 11.02.01 Outline the steps by which the polymerase chain reaction (PCR) amplifies a specific region of a genome.
Bloom’s: 2. Understand
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8) If a single DNA molecule is amplified by PCR, how many DNA molecules will exist after FIVE cycles?
A) 6
B) 8
C) 10
D) 32
E) 64

Answer: D
Section: 11.02
Topic: Genotyping a Known Disease-Causing Mutation
Learning Objective: 11.02.01 Outline the steps by which the polymerase chain reaction (PCR) amplifies a specific region of a genome.
Bloom’s: 3. Apply
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9) Allele-specific oligonucleotides (ASO) for the normal and disease alleles of a gene are in one section of a microarray. The disease is a recessive trait. If a probe made from an individual’s genomic DNA hybridizes with both ASOs, what can be inferred about the individual?
A) The individual has two normal alleles.
B) The individual has the disease.
C) 50% of the individual’s children are expected to be carriers.
D) One of the individual’s parents has the disease.

Answer: C
Section: 11.03
Topic: Sampling DNA Variation in a Genome
Learning Objective: 11.03.02 Describe how a DNA microarray is constructed and how to genotype millions of loci on this microarray.
Bloom’s: 3. Apply
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10) Positional cloning depends on knowing what?
A) the function of a gene
B) the expression pattern of a gene
C) the map location of markers that are linked to a gene
D) the sequence of a gene.

Answer: C
Section: 11.04
Topic: Positional Cloning
Learning Objective: 11.04.01 Describe the process of positional cloning and how it allows mapping of disease-causing mutations.
Bloom’s: 2. Understand
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