BSFS Bachelor of Science in Forensic Science MCQ 4 — Questions and Answers
Question 1: In forensic serology, the ABO blood type system is used because ABO antigens are present in:
- Only red blood cells
- Red blood cells and in secretions for approximately 80% of people (Correct answer)
- Only plasma
- White blood cells exclusively
Correct answer: Red blood cells and in secretions for approximately 80% of people
ABO antigens are found in red blood cells and, in approximately 80% of individuals (secretors), also in body fluids such as saliva and semen.
Question 2: What type of DNA marker is used in the CODIS database for criminal identification in the United States?
- Single nucleotide polymorphisms (SNPs)
- Short tandem repeats (STRs) (Correct answer)
- Mitochondrial DNA sequences
- Variable number tandem repeats (VNTRs)
Correct answer: Short tandem repeats (STRs)
CODIS uses short tandem repeat (STR) profiles at 20 core loci for comparing DNA evidence to offender profiles in its database.
Question 3: In questioned document examination, what does 'line quality' refer to?
- The ink density across a written line
- The smoothness, pen pressure, and continuity of strokes in handwriting (Correct answer)
- The straightness of printed text baselines
- The color consistency of typewritten characters
Correct answer: The smoothness, pen pressure, and continuity of strokes in handwriting
Line quality encompasses the smoothness, tremor, pen pressure, and continuity of strokes, which reveal whether writing was executed naturally or traced/forged.
Question 4: What is the main advantage of mitochondrial DNA (mtDNA) analysis over nuclear STR analysis in forensic cases?
- mtDNA provides a unique individual profile
- mtDNA is present in higher copy numbers and persists in degraded samples (Correct answer)
- mtDNA analysis is faster and cheaper
- mtDNA can identify the sex of an individual
Correct answer: mtDNA is present in higher copy numbers and persists in degraded samples
Mitochondrial DNA exists in hundreds to thousands of copies per cell, making it recoverable from highly degraded or old samples like hair shafts and ancient bones.
Question 5: Which reagent is used to detect latent fingerprints on porous surfaces such as paper?
- Cyanoacrylate fuming
- Ninhydrin (Correct answer)
- Magnetic powder
- Silver nitrate only
Correct answer: Ninhydrin
Ninhydrin reacts with amino acids left by the skin in latent prints on porous surfaces, producing a purple-colored compound (Ruhemann's purple).
Question 6: In forensic anthropology, what is the 'subpubic angle' used to determine?
- Age at death
- Biological sex (Correct answer)
- Stature estimation
- Ancestry estimation
Correct answer: Biological sex
The subpubic angle of the pelvis is wider in females than males, making it one of the most reliable skeletal indicators for determining biological sex.
Question 7: What does 'transfer evidence' mean in forensic science?
- Evidence moved from one jurisdiction to another
- Trace materials exchanged between a person and their environment during contact (Correct answer)
- Digital evidence transferred between devices
- Testimonial evidence given in a different court proceeding
Correct answer: Trace materials exchanged between a person and their environment during contact
Transfer evidence (trace evidence) refers to materials like fibers, hair, or soil exchanged between a person and their environment during physical contact, per Locard's principle.
BSFS Bachelor of Science in Forensic Science MCQ 4
In forensic serology, the ABO blood type system is used because ABO antigens are present in: