Practice Exam: CRIM - DNA & Forensic Biology (Set 41)
30-question practice exam on DNA profiling, biological evidence, and forensic serology.
1. Which of the following best describes the fundamental building block of a DNA molecule?
A.A Ribosome
B.A Nucleotide
C.An Amino Acid
D.A Protein
2. In the double helix structure of DNA, which nitrogenous base pairs with Adenine (A)?
A.Guanine (G)
B.Thymine (T)
C.Cytosine (C)
D.Uracil (U)
3. What is the term for a specific sequence of nucleotides in DNA that codes for a functional product, such as a protein?
A.A Chromosome
B.A Gene
C.An Allele
D.A Genome
4. What type of chemical bond holds the two strands of the DNA double helix together?
A.Covalent bond
B.Hydrogen bond
C.Ionic bond
D.Peptide bond
5. What is an allele?
A.The complete set of genetic material in an organism
B.A structure containing the DNA of an organism
C.A variant form of a given gene
D.A type of RNA molecule
6. Which DNA profiling method involves amplifying specific short, repeated sequences of DNA?
A.Restriction Fragment Length Polymorphism (RFLP)
B.Short Tandem Repeat (STR) Analysis
C.Southern Blotting
D.Sanger Sequencing
7. What is the primary purpose of the Polymerase Chain Reaction (PCR) in forensic DNA analysis?
A.To sequence the entire genome
B.To make millions of copies of a specific DNA segment
C.To separate DNA fragments by size
D.To identify the blood type from a sample
8. RFLP was one of the first DNA profiling techniques used in forensic science. What does "RFLP" stand for?
A.Random Fragment Length Polymorphism
B.Restriction Fragment Length Polymorphism
C.Repetitive Fragment Linkage Polymorphism
D.Rare Fragment Length Polymorphism
9. Why has STR analysis largely replaced RFLP in forensic science?
A.RFLP requires a larger sample of DNA
B.RFLP is less accurate than STR
C.RFLP cannot be automated
D.All of the above
10. In STR analysis, how are the different alleles distinguished from one another?
A.By the sequence of the bases
B.By the length of the repeat sequence
C.By the charge of the DNA molecule
D.By the type of sugar in the backbone
11. What is the most critical factor in the collection of biological evidence?
A.Using large collection containers
B.Preventing contamination
C.Documenting the temperature of the scene
D.Immediately freezing all samples
12. How should wet biological evidence, such as a blood-stained shirt, be packaged for transport to the lab?
A.In a sealed plastic bag to prevent leakage
B.In a paper bag or breathable container after air-drying
C.Folded neatly and placed in a standard evidence envelope
D.Sprayed with a preservative and sealed in a metal can
13. What is the "chain of custody" in the context of biological evidence?
A.The process of analyzing the evidence in the lab
B.The type of container used to store the evidence
C.A chronological written record of who handled the evidence
D.The specific location where the evidence was found
14. When collecting a reference DNA sample from a suspect, what is the most common and least invasive method?
A.Drawing a blood sample
B.A buccal (cheek) swab
C.Plucking a hair sample
D.Collecting a urine sample
15. Why is it important to collect and package items of evidence separately?
A.To save space in the evidence locker
B.To make the items easier to count
C.To prevent cross-contamination between items
D.To allow for faster analysis
16. The ABO blood group system is based on the presence or absence of which molecules on the surface of red blood cells?
A.Antibodies
B.Antigens
C.Hemoglobin
D.Platelets
17. A person with Type O blood has which antibodies in their plasma?
A.No antibodies
B.Anti-A antibodies only
C.Anti-B antibodies only
D.Both Anti-A and Anti-B antibodies
18. The Kastle-Meyer test is a presumptive test for which body fluid?
A.Semen
B.Blood
C.Saliva
D.Urine
19. What is the primary limitation of forensic serology for identification?
A.It is too expensive to perform
B.The tests are not reliable
C.It provides class characteristics, not individual characteristics
D.It can only be performed on fresh samples
20. An individual is found to be a "secretor." What does this mean?
A.Their blood type cannot be determined
B.They have a rare blood disorder
C.Their ABO blood type antigens are present in other body fluids
D.They do not produce antibodies
21. Which part of the hair is most useful for nuclear DNA analysis?
A.The cuticle
B.The medulla
C.The follicular tag (root)
D.The tip
22. What type of DNA is found in the shaft of a hair?
A.Nuclear DNA
B.Mitochondrial DNA (mtDNA)
C.Ribosomal DNA
D.Recombinant DNA
23. The microscopic examination of a hair can reliably determine all of the following EXCEPT:
A.Whether the hair is human or animal
B.The part of the body it came from
C.If the hair was forcibly removed
D.The age and sex of the individual
24. Which of the following is NOT one of the three main layers of the hair shaft?
A.Cuticle
B.Cortex
C.Follicle
D.Medulla
25. How is fiber evidence primarily classified?
A.By its length and width
B.As either natural or synthetic
C.By its color
D.By its manufacturer
26. What is the official title of Republic Act No. 10054?
A.The DNA Evidence Preservation Act of 2010
B.The Rules on DNA Evidence
C.The Forensic Biology and Genetics Act
D.The Criminal Investigation and DNA Act of 2010
27. Under the Rules on DNA Evidence (RA 10054), when may a court order DNA testing?
A.Only in criminal cases
B.Only in paternity disputes
C.In both criminal and civil cases where DNA is relevant
D.Only upon the request of the prosecution
28. What standard is used to assess the reliability and admissibility of DNA evidence in Philippine courts under RA 10054?
A.The Frye Standard
B.The Daubert Standard principles
C.The "Beyond Reasonable Doubt" standard
D.The "Clear and Convincing Evidence" standard
29. According to the Rules on DNA Evidence, what is the 'Post-Conviction DNA Testing' provision?
A.A rule that DNA testing can only happen after a conviction
B.A motion that can be filed by a convicted person to prove their innocence
C.A requirement to re-test all DNA evidence after a conviction
D.A standard for preserving DNA evidence post-trial
30. Who is responsible for assessing the probative value of the DNA evidence presented in court?
A.The DNA expert witness
B.The prosecution
C.The defense counsel
D.The judge