American Board Of Criminalistics
Forensic Dna Analyst Certification
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. Which molecule is the primary carrier of genetic information in human
cells?
A. RNA
B. DNA
C. Protein
D. Lipid
Rationale: DNA (deoxyribonucleic acid) stores hereditary information in
the nucleus of cells and is responsible for encoding genetic instructions
used in development, functioning, and reproduction. RNA primarily assists
in protein synthesis, while proteins and lipids serve structural and
metabolic roles rather than genetic storage.
2. The structure of DNA is best described as:
A. Single-stranded helix
B. Double-stranded antiparallel helix
C. Triple helix
D. Linear amino acid chain
Rationale: DNA consists of two antiparallel strands forming a double helix
, stabilized by hydrogen bonds between complementary bases. Single-
stranded forms exist in some viruses, but not in human genomic DNA.
3. Which nitrogenous base pairs with adenine in DNA?
A. Cytosine
B. Thymine
C. Uracil
D. Guanine
Rationale: Adenine pairs with thymine via two hydrogen bonds in DNA. In
RNA, adenine pairs with uracil instead of thymine.
4. Short tandem repeats (STRs) are best described as:
A. Large gene sequences
B. Repeating short DNA sequences used in identification
C. Protein-coding regions
D. Mitochondrial enzymes
Rationale: STRs are short repeated sequences of DNA (2–6 base pairs) that
vary greatly among individuals, making them ideal for forensic
identification.
5. PCR in forensic DNA analysis is used to:
A. Destroy contaminants
B. Amplify DNA regions
C. Sequence proteins
D. Separate chromosomes
Rationale: Polymerase Chain Reaction (PCR) amplifies specific DNA
regions, allowing analysis of minute or degraded samples.
6. The enzyme used in PCR to synthesize DNA is:
A. Ligase
B. Taq polymerase
C. Helicase
D. Restriction enzyme
Rationale: Taq polymerase is heat-stable and synthesizes DNA strands
during PCR cycles.
, 7. The main purpose of capillary electrophoresis in DNA analysis is to:
A. Amplify DNA
B. Separate DNA fragments by size
C. Extract DNA
D. Mutate DNA
Rationale: Capillary electrophoresis separates fluorescently labeled DNA
fragments based on size, enabling STR profiling.
8. A heterozygous STR locus contains:
A. Two identical alleles
B. Two different alleles
C. No alleles
D. Multiple chromosomes
Rationale: Heterozygous individuals possess two different alleles at a
locus, one inherited from each parent.
9. The purpose of an allele ladder in STR analysis is to:
A. Break DNA strands
B. Standardize allele sizing for comparison
C. Amplify DNA
D. Remove contamination
Rationale: Allele ladders provide reference fragment sizes to accurately
assign alleles in forensic samples.
10.Mitochondrial DNA is inherited primarily from:
A. Both parents equally
B. Father only
C. Mother only
D. Neither parent
Rationale: Mitochondrial DNA is maternally inherited because
mitochondria in sperm are typically not transmitted to offspring.
11.Nuclear DNA is found in:
A. Mitochondria
B. Ribosomes
Forensic Dna Analyst Certification
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which molecule is the primary carrier of genetic information in human
cells?
A. RNA
B. DNA
C. Protein
D. Lipid
Rationale: DNA (deoxyribonucleic acid) stores hereditary information in
the nucleus of cells and is responsible for encoding genetic instructions
used in development, functioning, and reproduction. RNA primarily assists
in protein synthesis, while proteins and lipids serve structural and
metabolic roles rather than genetic storage.
2. The structure of DNA is best described as:
A. Single-stranded helix
B. Double-stranded antiparallel helix
C. Triple helix
D. Linear amino acid chain
Rationale: DNA consists of two antiparallel strands forming a double helix
, stabilized by hydrogen bonds between complementary bases. Single-
stranded forms exist in some viruses, but not in human genomic DNA.
3. Which nitrogenous base pairs with adenine in DNA?
A. Cytosine
B. Thymine
C. Uracil
D. Guanine
Rationale: Adenine pairs with thymine via two hydrogen bonds in DNA. In
RNA, adenine pairs with uracil instead of thymine.
4. Short tandem repeats (STRs) are best described as:
A. Large gene sequences
B. Repeating short DNA sequences used in identification
C. Protein-coding regions
D. Mitochondrial enzymes
Rationale: STRs are short repeated sequences of DNA (2–6 base pairs) that
vary greatly among individuals, making them ideal for forensic
identification.
5. PCR in forensic DNA analysis is used to:
A. Destroy contaminants
B. Amplify DNA regions
C. Sequence proteins
D. Separate chromosomes
Rationale: Polymerase Chain Reaction (PCR) amplifies specific DNA
regions, allowing analysis of minute or degraded samples.
6. The enzyme used in PCR to synthesize DNA is:
A. Ligase
B. Taq polymerase
C. Helicase
D. Restriction enzyme
Rationale: Taq polymerase is heat-stable and synthesizes DNA strands
during PCR cycles.
, 7. The main purpose of capillary electrophoresis in DNA analysis is to:
A. Amplify DNA
B. Separate DNA fragments by size
C. Extract DNA
D. Mutate DNA
Rationale: Capillary electrophoresis separates fluorescently labeled DNA
fragments based on size, enabling STR profiling.
8. A heterozygous STR locus contains:
A. Two identical alleles
B. Two different alleles
C. No alleles
D. Multiple chromosomes
Rationale: Heterozygous individuals possess two different alleles at a
locus, one inherited from each parent.
9. The purpose of an allele ladder in STR analysis is to:
A. Break DNA strands
B. Standardize allele sizing for comparison
C. Amplify DNA
D. Remove contamination
Rationale: Allele ladders provide reference fragment sizes to accurately
assign alleles in forensic samples.
10.Mitochondrial DNA is inherited primarily from:
A. Both parents equally
B. Father only
C. Mother only
D. Neither parent
Rationale: Mitochondrial DNA is maternally inherited because
mitochondria in sperm are typically not transmitted to offspring.
11.Nuclear DNA is found in:
A. Mitochondria
B. Ribosomes
