FORENSIC BIOLOGY EXAM STUDY GUIDE
2026 COMPLETE QUESTIONS WITH
CORRECT DETAILED ANSWERS AND
RATIONALES || 100% GUARANTEED PASS
<LATEST VERSION>
FORENSIC BIOLOGY EXAM STUDY GUIDE 2026
1. What is the primary function of a forensic biologist at a crime scene?
A) To interrogate suspects
B) To analyze financial records
C) To identify, collect, and preserve biological evidence
D) To perform the autopsy
Answer: C) To identify, collect, and preserve biological evidence
Rationale: Forensic biologists are evidence specialists. Their core duty at a scene is
to recognize potential biological materials (blood, semen, hair, etc.), ensure their
proper collection to avoid contamination, and preserve their integrity for
laboratory analysis.
2. Which of the following is an example of individual characteristics in evidence?
A) Blood type AB-
B) A DNA profile from a single-source sample
C) Red cotton fibers
D) The ABO blood group system
Answer: B) A DNA profile from a single-source sample
Rationale: Individual characteristics can be linked to a single, specific source with
high certainty. A full DNA profile is unique to an individual (except identical twins),
whereas blood types and fiber types are class characteristics shared by many
people or items.
,3. Luminol is a chemical used to detect the presence of:
A) Saliva
B) Blood, even if it has been cleaned
C) Semen
D) Fingernails
Answer: B) Blood, even if it has been cleaned
Rationale: Luminol reacts with the hemoglobin in blood, producing a
chemiluminescent (blue) glow. It is extremely sensitive and can detect trace
amounts of blood that are invisible to the naked eye, even after attempts to clean
the scene.
4. The confirmatory test for the presence of semen is the identification of:
A) Acid Phosphatase (AP)
B) Prostate-Specific Antigen (PSA)
C) Spermatozoa under a microscope
D) Amylase
Answer: C) Spermatozoa under a microscope
Rationale: While Acid Phosphatase is a highly sensitive presumptive test for
semen, the only confirmatory test is the direct visual observation of sperm cells
(spermatozoa) via microscopy.
5. Which part of the hair is most suitable for nuclear DNA analysis?
A) The tip
B) The shaft
C) The root bulb
D) The cuticle
Answer: C) The root bulb
Rationale: Nuclear DNA is found in the nucleus of a cell. The root bulb contains
nucleated cells that are actively dividing. The hair shaft itself is primarily
composed of keratinized, dead cells and contains minimal nuclear DNA.
6. Mitochondrial DNA (mtDNA) is inherited solely from:
A) The father
B) The mother
,C) Both parents equally
D) It is a random mutation
Answer: B) The mother
Rationale: MtDNA is located in the mitochondria of the egg cell, not the sperm.
Therefore, an individual's mtDNA is identical to their mother's, their maternal
grandmother's, and so on.
7. What is the purpose of the Polymerase Chain Reaction (PCR) in forensic DNA
analysis?
A) To cut DNA at specific sequences
B) To create a visual fingerprint pattern
C) To make millions of copies of a specific DNA region
D) To separate DNA fragments by size
Answer: C) To make millions of copies of a specific DNA region
Rationale: PCR is a molecular "photocopier." It allows scientists to amplify very
small or degraded DNA samples from evidence into quantities large enough for
analysis and profiling.
8. Short Tandem Repeats (STRs) are:
A) Long, repeating sequences of RNA
B) Sections of DNA that code for proteins
C) Short, repeating sequences of 2-6 base pairs used for DNA profiling
D) The same as Mitochondrial DNA
Answer: C) Short, repeating sequences of 2-6 base pairs used for DNA profiling
Rationale: STRs are the current standard for forensic DNA profiling. The number
of repeats at specific chromosomal locations (loci) is highly variable between
individuals, creating a unique genetic fingerprint.
9. CODIS is:
A) A chemical used to develop fingerprints
B) A technique for blood spatter analysis
C) The national DNA database in the United States
D) A type of confirmatory test for saliva
Answer: C) The national DNA database in the United States
, Rationale: The Combined DNA Index System (CODIS) is the FBI's software that
allows local, state, and national crime labs to compare and exchange DNA profiles.
10. Which of the following best describes "touch DNA"?
A) DNA from a blood sample
B) DNA from skin cells transferred via contact
C) DNA extracted from bone
D) DNA from a saliva sample
Answer: B) DNA from skin cells transferred via contact
Rationale: "Touch DNA" refers to the trace amounts of DNA deposited when a
person touches an object. This DNA comes from shed skin cells.
11. A presumptive test for blood:
A) Is confirmatory and specific
B) Can identify the species of origin
C) Is used to screen for the possible presence of blood
D) Is always the Kastle-Meyer test
Answer: C) Is used to screen for the possible presence of blood
Rationale: Presumptive tests are sensitive, cheap, and quick screening tools. They
indicate that a substance might be blood but can also yield false positives from
other substances.
12. Which body fluid is typically identified by the presence of high levels of
amylase?
A) Blood
B) Semen
C) Vaginal Secretions
D) Saliva
Answer: D) Saliva
Rationale: Amylase is an enzyme that breaks down starch. It is found in high
concentrations in saliva, making it the target for presumptive tests for saliva.
13. The serological test that distinguishes between human and animal blood is
called a(n):
2026 COMPLETE QUESTIONS WITH
CORRECT DETAILED ANSWERS AND
RATIONALES || 100% GUARANTEED PASS
<LATEST VERSION>
FORENSIC BIOLOGY EXAM STUDY GUIDE 2026
1. What is the primary function of a forensic biologist at a crime scene?
A) To interrogate suspects
B) To analyze financial records
C) To identify, collect, and preserve biological evidence
D) To perform the autopsy
Answer: C) To identify, collect, and preserve biological evidence
Rationale: Forensic biologists are evidence specialists. Their core duty at a scene is
to recognize potential biological materials (blood, semen, hair, etc.), ensure their
proper collection to avoid contamination, and preserve their integrity for
laboratory analysis.
2. Which of the following is an example of individual characteristics in evidence?
A) Blood type AB-
B) A DNA profile from a single-source sample
C) Red cotton fibers
D) The ABO blood group system
Answer: B) A DNA profile from a single-source sample
Rationale: Individual characteristics can be linked to a single, specific source with
high certainty. A full DNA profile is unique to an individual (except identical twins),
whereas blood types and fiber types are class characteristics shared by many
people or items.
,3. Luminol is a chemical used to detect the presence of:
A) Saliva
B) Blood, even if it has been cleaned
C) Semen
D) Fingernails
Answer: B) Blood, even if it has been cleaned
Rationale: Luminol reacts with the hemoglobin in blood, producing a
chemiluminescent (blue) glow. It is extremely sensitive and can detect trace
amounts of blood that are invisible to the naked eye, even after attempts to clean
the scene.
4. The confirmatory test for the presence of semen is the identification of:
A) Acid Phosphatase (AP)
B) Prostate-Specific Antigen (PSA)
C) Spermatozoa under a microscope
D) Amylase
Answer: C) Spermatozoa under a microscope
Rationale: While Acid Phosphatase is a highly sensitive presumptive test for
semen, the only confirmatory test is the direct visual observation of sperm cells
(spermatozoa) via microscopy.
5. Which part of the hair is most suitable for nuclear DNA analysis?
A) The tip
B) The shaft
C) The root bulb
D) The cuticle
Answer: C) The root bulb
Rationale: Nuclear DNA is found in the nucleus of a cell. The root bulb contains
nucleated cells that are actively dividing. The hair shaft itself is primarily
composed of keratinized, dead cells and contains minimal nuclear DNA.
6. Mitochondrial DNA (mtDNA) is inherited solely from:
A) The father
B) The mother
,C) Both parents equally
D) It is a random mutation
Answer: B) The mother
Rationale: MtDNA is located in the mitochondria of the egg cell, not the sperm.
Therefore, an individual's mtDNA is identical to their mother's, their maternal
grandmother's, and so on.
7. What is the purpose of the Polymerase Chain Reaction (PCR) in forensic DNA
analysis?
A) To cut DNA at specific sequences
B) To create a visual fingerprint pattern
C) To make millions of copies of a specific DNA region
D) To separate DNA fragments by size
Answer: C) To make millions of copies of a specific DNA region
Rationale: PCR is a molecular "photocopier." It allows scientists to amplify very
small or degraded DNA samples from evidence into quantities large enough for
analysis and profiling.
8. Short Tandem Repeats (STRs) are:
A) Long, repeating sequences of RNA
B) Sections of DNA that code for proteins
C) Short, repeating sequences of 2-6 base pairs used for DNA profiling
D) The same as Mitochondrial DNA
Answer: C) Short, repeating sequences of 2-6 base pairs used for DNA profiling
Rationale: STRs are the current standard for forensic DNA profiling. The number
of repeats at specific chromosomal locations (loci) is highly variable between
individuals, creating a unique genetic fingerprint.
9. CODIS is:
A) A chemical used to develop fingerprints
B) A technique for blood spatter analysis
C) The national DNA database in the United States
D) A type of confirmatory test for saliva
Answer: C) The national DNA database in the United States
, Rationale: The Combined DNA Index System (CODIS) is the FBI's software that
allows local, state, and national crime labs to compare and exchange DNA profiles.
10. Which of the following best describes "touch DNA"?
A) DNA from a blood sample
B) DNA from skin cells transferred via contact
C) DNA extracted from bone
D) DNA from a saliva sample
Answer: B) DNA from skin cells transferred via contact
Rationale: "Touch DNA" refers to the trace amounts of DNA deposited when a
person touches an object. This DNA comes from shed skin cells.
11. A presumptive test for blood:
A) Is confirmatory and specific
B) Can identify the species of origin
C) Is used to screen for the possible presence of blood
D) Is always the Kastle-Meyer test
Answer: C) Is used to screen for the possible presence of blood
Rationale: Presumptive tests are sensitive, cheap, and quick screening tools. They
indicate that a substance might be blood but can also yield false positives from
other substances.
12. Which body fluid is typically identified by the presence of high levels of
amylase?
A) Blood
B) Semen
C) Vaginal Secretions
D) Saliva
Answer: D) Saliva
Rationale: Amylase is an enzyme that breaks down starch. It is found in high
concentrations in saliva, making it the target for presumptive tests for saliva.
13. The serological test that distinguishes between human and animal blood is
called a(n):
