Test Bank –
Molecular Diagnostics: Fundamentals, Methods, and Clinical
Applications,
By Buckingham
4th edition
,Table of contents
1: Nucleic Acids
2: Genotype to Phenotype
3: Gene Expression and Epigenetics
4: Collection, Isolation, and Quantification of Nucleic Acids
5: Resolution and Detection of Nucleic Acids
6: Analysis and Characterization of Nucleic Acids and Proteins
7: Nucleic Acid Amplification
8: Human Chromosomal Structure and Structural Variants
9: Targeted Variant Detection
10: Molecular Sequencing
11: Molecular Variants and Human Identification
12: Detection and Identification of Microorganisms
13: Molecular Detection of Inherited Diseases
14: Molecular Oncology
15: DNA-Based Tissue Typing
16: Quality Assurance and Quality Control in the Molecular Laboratory
,Molecular Diagnostics: Fundamentals, Methods, and
Clinical Applications, 4th Edition — Buckingham
CHAPTER 1: NUCLEIC ACIDS
1. Which of the following best describes the structural difference between DNA
and RNA?
A) DNA contains uracil; RNA contains thymine
B) DNA contains a 2′-hydroxyl group on the ribose sugar; RNA does not
C) DNA contains deoxyribose sugar and thymine; RNA contains ribose sugar and
uracil
D) DNA is single-stranded; RNA is double-stranded
Answer: C
Rationale: DNA contains the sugar 2′-deoxyribose and the nitrogenous base
thymine, whereas RNA contains ribose (with a 2′-OH group) and uracil in place of
thymine. This fundamental chemical distinction underlies many of the functional
and stability differences between the two nucleic acids.
2. The phosphodiester bond in a nucleic acid strand links:
A) The 5′ phosphate of one nucleotide to the 3′ hydroxyl of the next
B) The 3′ phosphate of one nucleotide to the 5′ hydroxyl of the next
C) Two adjacent nitrogenous bases
D) The sugar to the nitrogenous base
Answer: A
Rationale: Phosphodiester bonds connect the 5′ phosphate group of one
nucleotide to the 3′ hydroxyl group of the adjacent nucleotide, creating the sugar-
phosphate backbone with inherent 5′→3′ directionality.
3. According to Chargaff's rules, which relationship holds true for double-
stranded DNA?
A) A = G and T = C
, B) A = T and G = C
C) A = C and G = T
D) A + T = G + C
Answer: B
Rationale: Chargaff's rules state that in double-stranded DNA, the amount of
adenine equals thymine (A = T) and guanine equals cytosine (G = C) due to
complementary base pairing. The ratio of (A+T) to (G+C) varies between species.
4. The melting temperature (Tm) of a DNA duplex is primarily influenced by:
A) The length of the DNA and its GC content
B) The presence of uracil residues
C) The number of phosphodiester bonds
D) The concentration of RNA in the sample
Answer: A
Rationale: Tm is the temperature at which 50% of the DNA duplex dissociates into
single strands. Higher GC content (three hydrogen bonds per pair vs. two for AT)
and longer sequences both increase Tm. Salt concentration also plays a role.
5. Which type of RNA carries amino acids to the ribosome during translation?
A) mRNA
B) rRNA
C) tRNA
D) snRNA
Answer: C
Rationale: Transfer RNA (tRNA) has a cloverleaf secondary structure with an
anticodon loop that recognizes mRNA codons and an acceptor stem to which the
appropriate amino acid is attached, delivering it to the ribosome during protein
synthesis.
6. The antiparallel nature of the DNA double helix means that:
A) Both strands run 5′→3′ in the same direction
Molecular Diagnostics: Fundamentals, Methods, and Clinical
Applications,
By Buckingham
4th edition
,Table of contents
1: Nucleic Acids
2: Genotype to Phenotype
3: Gene Expression and Epigenetics
4: Collection, Isolation, and Quantification of Nucleic Acids
5: Resolution and Detection of Nucleic Acids
6: Analysis and Characterization of Nucleic Acids and Proteins
7: Nucleic Acid Amplification
8: Human Chromosomal Structure and Structural Variants
9: Targeted Variant Detection
10: Molecular Sequencing
11: Molecular Variants and Human Identification
12: Detection and Identification of Microorganisms
13: Molecular Detection of Inherited Diseases
14: Molecular Oncology
15: DNA-Based Tissue Typing
16: Quality Assurance and Quality Control in the Molecular Laboratory
,Molecular Diagnostics: Fundamentals, Methods, and
Clinical Applications, 4th Edition — Buckingham
CHAPTER 1: NUCLEIC ACIDS
1. Which of the following best describes the structural difference between DNA
and RNA?
A) DNA contains uracil; RNA contains thymine
B) DNA contains a 2′-hydroxyl group on the ribose sugar; RNA does not
C) DNA contains deoxyribose sugar and thymine; RNA contains ribose sugar and
uracil
D) DNA is single-stranded; RNA is double-stranded
Answer: C
Rationale: DNA contains the sugar 2′-deoxyribose and the nitrogenous base
thymine, whereas RNA contains ribose (with a 2′-OH group) and uracil in place of
thymine. This fundamental chemical distinction underlies many of the functional
and stability differences between the two nucleic acids.
2. The phosphodiester bond in a nucleic acid strand links:
A) The 5′ phosphate of one nucleotide to the 3′ hydroxyl of the next
B) The 3′ phosphate of one nucleotide to the 5′ hydroxyl of the next
C) Two adjacent nitrogenous bases
D) The sugar to the nitrogenous base
Answer: A
Rationale: Phosphodiester bonds connect the 5′ phosphate group of one
nucleotide to the 3′ hydroxyl group of the adjacent nucleotide, creating the sugar-
phosphate backbone with inherent 5′→3′ directionality.
3. According to Chargaff's rules, which relationship holds true for double-
stranded DNA?
A) A = G and T = C
, B) A = T and G = C
C) A = C and G = T
D) A + T = G + C
Answer: B
Rationale: Chargaff's rules state that in double-stranded DNA, the amount of
adenine equals thymine (A = T) and guanine equals cytosine (G = C) due to
complementary base pairing. The ratio of (A+T) to (G+C) varies between species.
4. The melting temperature (Tm) of a DNA duplex is primarily influenced by:
A) The length of the DNA and its GC content
B) The presence of uracil residues
C) The number of phosphodiester bonds
D) The concentration of RNA in the sample
Answer: A
Rationale: Tm is the temperature at which 50% of the DNA duplex dissociates into
single strands. Higher GC content (three hydrogen bonds per pair vs. two for AT)
and longer sequences both increase Tm. Salt concentration also plays a role.
5. Which type of RNA carries amino acids to the ribosome during translation?
A) mRNA
B) rRNA
C) tRNA
D) snRNA
Answer: C
Rationale: Transfer RNA (tRNA) has a cloverleaf secondary structure with an
anticodon loop that recognizes mRNA codons and an acceptor stem to which the
appropriate amino acid is attached, delivering it to the ribosome during protein
synthesis.
6. The antiparallel nature of the DNA double helix means that:
A) Both strands run 5′→3′ in the same direction
