2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
Test Bank – Chapter 1: The Molecular Basis of Heredity, Variation, and
Evolution
1. Rosalind Franklin’s X-ray diffraction pattern of DNA most directly
provided which piece of structural information?
A) The exact base-pairing rules between nucleotides
B) That DNA is single-stranded in certain viruses
C) The regular helical nature and dimensions of the molecule
D) The enzymatic mechanism for DNA replication
E) That DNA contains deoxyribose instead of ribose
✅ Correct Answer: C
Rationale: Franklin’s X-ray diffraction images revealed a repeating helical
pattern with specific dimensions (diameter ~2 nm, helical pitch ~3.4 nm,
and 10 bases per turn). While her data didn’t show base-pairing rules
directly, they were critical for Watson and Crick’s double-helix model.
Skill: Understanding
2. What is “central dogma” of molecular biology best described as?
A) DNA replication → RNA transcription → protein translation
B) Protein synthesis → RNA processing → DNA storage
C) RNA transcription → protein synthesis → DNA degradation
D) DNA transcription → RNA replication → protein assembly
E) Protein folding → RNA modification → DNA synthesis
✅ Correct Answer: A
Rationale: The central dogma states that information flows from DNA to
RNA (transcription) and then to protein (translation). Replication is the
process by which DNA is duplicated prior to cell division, maintaining
genetic information.
Skill: Remembering
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
3. A scientist discovers a new organism in which genetic information is
stored in RNA rather than DNA. Which conclusion is most consistent
with this finding?
A) The organism must be a bacterium
B) It is likely a retrovirus or RNA virus
C) Its RNA will not be subject to mutation
D) It cannot undergo recombination
E) It must use DNA polymerase to replicate
✅ Correct Answer: B
Rationale: Some viruses (e.g., retroviruses, positive-sense RNA viruses)
store their genome as RNA. They use specialized enzymes like reverse
transcriptase (retroviruses) or RNA-dependent RNA polymerase to
replicate.
Skill: Applying
4. Which mechanism would most directly increase allelic diversity within a
sexually reproducing population without altering chromosome number?
A) Nondisjunction during meiosis
B) Synapsis and crossing over between homologous chromosomes
C) Gene duplication events
D) Chromosome fusion
E) Mitotic recombination
✅ Correct Answer: B
Rationale: Crossing over during prophase I of meiosis exchanges genetic
material between homologous chromosomes, generating novel allele
combinations without changing chromosome number.
Skill: Understanding
5. A mutation changes a codon from UAU (tyrosine) to UAA (stop codon).
What is this mutation is classified as?
A) Missense
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
B) Silent
C) Nonsense
D) Frameshift
E) Synonymous
✅ Correct Answer: C
Rationale: A nonsense mutation converts a codon for an amino acid into a
stop codon, resulting in premature termination of translation. This can
significantly disrupt protein function.
Skill: Remembering
6. In Griffith’s transformation experiment, what was the most critical
observation?
A) Heat-killed smooth strain bacteria could be revived by rough strain
bacteria
B) DNA was identified as the transforming principle
C) A non-virulent strain became virulent after exposure to heat-killed
virulent strain
D) Protein was shown to carry genetic information
E) RNA was required for transformation
✅ Correct Answer: C
Rationale: Griffith demonstrated that non-virulent rough strain
pneumococci could acquire virulence when exposed to heat-killed smooth
strain cells, suggesting the transfer of a “transforming principle” later
identified as DNA.
Skill: Understanding
7. Which type of mutation would most likely have no effect on the
phenotype?
A) Silent mutation in the third position of a codon
B) Nonsense mutation early in a coding sequence
C) Frameshift mutation in exon 1
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
D) Large deletion of coding sequence
E) Missense mutation in an enzyme active site
✅ Correct Answer: A
Rationale: Silent mutations often occur in the wobble position of codons,
leading to no change in the encoded amino acid due to redundancy in the
genetic code. The phenotype is usually unaffected unless regulatory
elements are impacted.
Skill: Applying
8. Which evolutionary process can increase the frequency of a harmful
allele in a small population due to chance alone?
A) Natural selection
B) Genetic drift
C) Gene flow
D) Positive selection
E) Mutation pressure
✅ Correct Answer: B
Rationale: In small populations, random fluctuations in allele frequencies
(genetic drift) can cause harmful alleles to become more common or fixed,
independent of selective advantage.
Skill: Understanding
9. Which statement best explains why recombination is important in
evolution?
A) It eliminates all harmful mutations from a population
B) It generates new combinations of alleles that selection can act upon
C) It increases the mutation rate in a population
D) It prevents chromosomal segregation errors
E) It ensures equal numbers of males and females
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
✅ Correct Answer: B
Rationale: Recombination shuffles existing genetic variation, producing
novel genotypes that may be advantageous and subject to natural
selection, thus promoting evolutionary change.
Skill: Analyzing
10. What was Hershey-Chase experiment that used bacteriophages labeled
with radioactive isotopes used to show?
A) Proteins, not DNA, are the genetic material
B) DNA is the genetic material in phages
C) RNA is required for viral replication
D) Protein coats enter bacterial cells during infection
E) DNA and protein contribute equally to heredity
✅ Correct Answer: B
Rationale: By labeling DNA with ³²P and protein with ³⁵S, Hershey and
Chase demonstrated that only the DNA entered the bacterial cell and
directed the production of new phages, confirming DNA as the hereditary
material.
Skill: Understanding
11. Which of the following is a direct consequence of the degeneracy of the
genetic code?
A) One gene can code for multiple proteins
B) Multiple codons can code for the same amino acid
C) Codons overlap in the reading frame
D) Each codon specifies more than one amino acid
E) Frameshifts are tolerated
✅ Correct Answer: B
Rationale: The genetic code is degenerate, meaning that several different
codons can specify the same amino acid, contributing to mutation
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
Test Bank – Chapter 1: The Molecular Basis of Heredity, Variation, and
Evolution
1. Rosalind Franklin’s X-ray diffraction pattern of DNA most directly
provided which piece of structural information?
A) The exact base-pairing rules between nucleotides
B) That DNA is single-stranded in certain viruses
C) The regular helical nature and dimensions of the molecule
D) The enzymatic mechanism for DNA replication
E) That DNA contains deoxyribose instead of ribose
✅ Correct Answer: C
Rationale: Franklin’s X-ray diffraction images revealed a repeating helical
pattern with specific dimensions (diameter ~2 nm, helical pitch ~3.4 nm,
and 10 bases per turn). While her data didn’t show base-pairing rules
directly, they were critical for Watson and Crick’s double-helix model.
Skill: Understanding
2. What is “central dogma” of molecular biology best described as?
A) DNA replication → RNA transcription → protein translation
B) Protein synthesis → RNA processing → DNA storage
C) RNA transcription → protein synthesis → DNA degradation
D) DNA transcription → RNA replication → protein assembly
E) Protein folding → RNA modification → DNA synthesis
✅ Correct Answer: A
Rationale: The central dogma states that information flows from DNA to
RNA (transcription) and then to protein (translation). Replication is the
process by which DNA is duplicated prior to cell division, maintaining
genetic information.
Skill: Remembering
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
3. A scientist discovers a new organism in which genetic information is
stored in RNA rather than DNA. Which conclusion is most consistent
with this finding?
A) The organism must be a bacterium
B) It is likely a retrovirus or RNA virus
C) Its RNA will not be subject to mutation
D) It cannot undergo recombination
E) It must use DNA polymerase to replicate
✅ Correct Answer: B
Rationale: Some viruses (e.g., retroviruses, positive-sense RNA viruses)
store their genome as RNA. They use specialized enzymes like reverse
transcriptase (retroviruses) or RNA-dependent RNA polymerase to
replicate.
Skill: Applying
4. Which mechanism would most directly increase allelic diversity within a
sexually reproducing population without altering chromosome number?
A) Nondisjunction during meiosis
B) Synapsis and crossing over between homologous chromosomes
C) Gene duplication events
D) Chromosome fusion
E) Mitotic recombination
✅ Correct Answer: B
Rationale: Crossing over during prophase I of meiosis exchanges genetic
material between homologous chromosomes, generating novel allele
combinations without changing chromosome number.
Skill: Understanding
5. A mutation changes a codon from UAU (tyrosine) to UAA (stop codon).
What is this mutation is classified as?
A) Missense
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
B) Silent
C) Nonsense
D) Frameshift
E) Synonymous
✅ Correct Answer: C
Rationale: A nonsense mutation converts a codon for an amino acid into a
stop codon, resulting in premature termination of translation. This can
significantly disrupt protein function.
Skill: Remembering
6. In Griffith’s transformation experiment, what was the most critical
observation?
A) Heat-killed smooth strain bacteria could be revived by rough strain
bacteria
B) DNA was identified as the transforming principle
C) A non-virulent strain became virulent after exposure to heat-killed
virulent strain
D) Protein was shown to carry genetic information
E) RNA was required for transformation
✅ Correct Answer: C
Rationale: Griffith demonstrated that non-virulent rough strain
pneumococci could acquire virulence when exposed to heat-killed smooth
strain cells, suggesting the transfer of a “transforming principle” later
identified as DNA.
Skill: Understanding
7. Which type of mutation would most likely have no effect on the
phenotype?
A) Silent mutation in the third position of a codon
B) Nonsense mutation early in a coding sequence
C) Frameshift mutation in exon 1
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
D) Large deletion of coding sequence
E) Missense mutation in an enzyme active site
✅ Correct Answer: A
Rationale: Silent mutations often occur in the wobble position of codons,
leading to no change in the encoded amino acid due to redundancy in the
genetic code. The phenotype is usually unaffected unless regulatory
elements are impacted.
Skill: Applying
8. Which evolutionary process can increase the frequency of a harmful
allele in a small population due to chance alone?
A) Natural selection
B) Genetic drift
C) Gene flow
D) Positive selection
E) Mutation pressure
✅ Correct Answer: B
Rationale: In small populations, random fluctuations in allele frequencies
(genetic drift) can cause harmful alleles to become more common or fixed,
independent of selective advantage.
Skill: Understanding
9. Which statement best explains why recombination is important in
evolution?
A) It eliminates all harmful mutations from a population
B) It generates new combinations of alleles that selection can act upon
C) It increases the mutation rate in a population
D) It prevents chromosomal segregation errors
E) It ensures equal numbers of males and females
, 2025 Test bank for Genetic Analysis: An Integrated Approach, 3rd Edition
✅ Correct Answer: B
Rationale: Recombination shuffles existing genetic variation, producing
novel genotypes that may be advantageous and subject to natural
selection, thus promoting evolutionary change.
Skill: Analyzing
10. What was Hershey-Chase experiment that used bacteriophages labeled
with radioactive isotopes used to show?
A) Proteins, not DNA, are the genetic material
B) DNA is the genetic material in phages
C) RNA is required for viral replication
D) Protein coats enter bacterial cells during infection
E) DNA and protein contribute equally to heredity
✅ Correct Answer: B
Rationale: By labeling DNA with ³²P and protein with ³⁵S, Hershey and
Chase demonstrated that only the DNA entered the bacterial cell and
directed the production of new phages, confirming DNA as the hereditary
material.
Skill: Understanding
11. Which of the following is a direct consequence of the degeneracy of the
genetic code?
A) One gene can code for multiple proteins
B) Multiple codons can code for the same amino acid
C) Codons overlap in the reading frame
D) Each codon specifies more than one amino acid
E) Frameshifts are tolerated
✅ Correct Answer: B
Rationale: The genetic code is degenerate, meaning that several different
codons can specify the same amino acid, contributing to mutation
