Forensic Biology and DNA Analysis – Blood, Semen, and Skeletal Remains Practice Exam

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• Which statement best describes the relationship between BAC and brain concentration of alcohol?
• Which substances commonly inhibit DNA analysis from bone or soil, and how can labs mitigate them?
• Which factors influence decomposition?
• What is the size range of spermatozoa?
• What is the main method of alcohol elimination in the body?
• What is allele drop-in and how can it affect interpretation?
• What defines the rifling method of a barrel?
• Narcotics are drugs that relieve pain and produce sleep. Which of the following best fits this category?
• Casting shoe impressions requires which material?
• What challenge does mixed-origin DNA samples pose for statistical interpretation, and what general approach is used?
• What is the basis for determining age from skeletal remains?
• What is the significance of Y-STRs in forensic DNA analysis?
• Which term describes the time when insects begin colonizing a body, including pre-colonization by myiasis?
• Which of the following is an application of determining Post Mortem Interval?
• Which statement correctly lists the order of the five stages of decomposition?
• What is touch DNA?
• Livor mortis refers to which finding?
• What is the role of proficiency testing in forensic DNA labs?
• Which of the following is NOT typically considered a depressant?
• Which of the following is a common symptom of withdrawal from physical dependence?
• What is the role of blowflies in forensic entomology?
• How does DNA evidence from skeletal remains contribute to a presumptive identification?
• Which cranial characteristics are associated with male sex determination?
• What should be done to collect loose foreign material from a victim?
• Which statement best differentiates physical dependence from psychological dependence?
• Impression preservation at a crime scene requires which combination of steps?
• What type of drugs are easily extracted from alkaline solutions?
• What challenges exist in microscopic examination of spermatozoa?
• In interpreting STR profiles, why can allele dropout lead to misinterpretation of the number of contributors?
• OxyContin is used for the treatment of chronic pain and is mainly made of which active ingredient?
• What chemical is responsible for marijuana's psychoactive effects?
• Living (motile) sperm survival in the vaginal cavity is approximately
• If a person lacks the D antigen, what is their Rh status?
• What is a mini-STR analysis and when is it advantageous?
• The Dry Stage is characterized by which condition?
• What are striations in firearms identification?
• What is the purpose of reporting likelihood ratios in DNA evidence interpretation?
• Which statement correctly describes how alcohol is eliminated from the body?
• What is the purpose of chromatography in drug analysis?
• What is the purpose of DNA polymerase in forensic analysis?
• Which blood type has A antigens and anti-B antibodies?
• Which stage is defined by the body being reduced to bones, cartilage, and dry skin?
• What unit is used to express the length of human spermatozoa?
• Which statement about Takayama and Teichmann tests is correct?
• Which method studies the predictable sequence of insects attracted to a decomposing body?
• In forensic biology, the significance of PSA is that
• Which practice is recommended when interpreting two-person DNA mixtures to minimize misattribution?
• In forensic investigations, luminol is known to
• How does Massively Parallel Sequencing (MPS/NGS) differ from traditional STR analysis?
• List two confirmatory semen tests and what each detects?
• What is CODIS?
• What is the role of peroxidases in the Kastle-Meyer test?
• Which blood type has both A and B antigens?
• Which guidelines govern forensic DNA method validation and reporting, and what do they address?
• Which statement best describes the Greenbottle fly in forensic cases?
• What characterizes the Bloated Stage of decomposition?
• What is forensic entomology?
• What is the recommended method for collecting rape evidence?
• What is the first method used to determine Post Mortem Interval?
• During the Fresh Stage of decomposition, which occurs?
• Which blood type has B antigens and anti-A antibodies?
• Rigor mortis is best described as?
• What is a common conclusion about using Amelogenin for sex determination across populations?
• What is the function of an extraction blank in the DNA workflow?
• Why is accurate allele sizing critical in STR analysis?
• Non-motile sperm can be found for up to
• What does Time of Colonization (TOC) refer to?
• Which statement describes the AMELX/AMELY caveat in sex determination and its interpretation?
• In forensic toxicology, which specimens are commonly analyzed?
• Spongy bone makes up about what percentage of skeletal mass?
• How many DNA-containing cells are needed for STR analysis?
• Depressants are used to?
• What is the average elimination rate of alcohol from the body?
• Oxycodone is the active ingredient in which medication?
• When nuclear DNA is unrecoverable, which type of DNA is commonly used and why?
• Which statement best describes Y-STRs in forensic DNA analysis?
• What are the main components of plasma?
• In the context of courtroom admissibility, which statement is true?
• The precipitin test determines
• What is the significance of long bone length in determining stature?
• Takayama and Teichmann tests are used to
• Which test is used to detect the presence of seminal fluid?
• What causes the bloated appearance during decomposition?
• In forensic toxicology, which statement is not accurate?
• How should impressions be preserved at a crime scene?
• What is the relationship between antigens and antibodies?
• Which statement about Y-STRs is true?
• What is the purpose of DNA quantification in a forensic workflow?
• CODIS stores DNA profiles from which categories?
• What reagent is commonly used to decalcify bone during DNA extraction, and why?
• What is cortical bone?
• What is the main purpose of the polymerase chain reaction (PCR) in forensic DNA analysis?
• What are the common types of handguns?
• Touch DNA refers to DNA obtained from skin cells transferred onto objects such as weapons or gloves.
• Algor mortis refers to what postmortem change?
• Which test is used as a presumptive indicator of blood based on hemoglobin's peroxidase-like activity?
• Why is hair analysis useful in drug testing?
• What is the difference between intra-laboratory and inter-laboratory reproducibility, and why is it important?
• Which best describes the role of Y-chromosome STRs in sexual assault investigations?
• What is the purpose of reporting a degradation index and how does it influence downstream testing?
• Which statement about temperature and insect development is true?
• During which stage is the body described as being in the Fresh Stage with little morphological change and no odor?
• Which statement best describes gel electrophoresis compared to capillary electrophoresis?
• In rifling, what do the terms lands and grooves describe?
• In sexual assault investigations, what is the primary use of Y-chromosome STRs when female DNA is the major contributor?
• Which blood type has neither A nor B antigens?
• What is the sensitivity level of accepted protocols for biological evidence?
• Which blood type has neither A nor B antigens?
• What are Y-STRs and in what scenario are they particularly useful?
• Which statement best describes the effect of stimulants on the central nervous system?
• Why is mitochondrial DNA often useful in disaster victim identification?
• What is the purpose of semen presumptive testing and name one common example?
• What is the role of a chemist in forensic toxicology?
• Which statement best describes the primary readout in capillary electrophoresis-based STR analysis?
• What are the two phases of drug identification?
• The number of ossification centers in humans is a useful metric for what?
• What is the role of a toxicologist in forensic toxicology?
• Which statement best explains why short STR targets are preferred in degraded DNA analysis?
• Which test is commonly used to rapidly detect semen-specific proteins in a sample after presumptive testing?
• Which statement best describes the purpose of proficiency testing in forensic labs?
• What kind of DNA data is particularly helpful when DNA is scarce or degraded?
• Why is proper packaging of biological evidence important?
• Hallucinogens are known to induce which of the following?
• What is serum?
• What is a DNA degradation index and how is it used?
• What is the purpose of facial reconstruction in forensic anthropology?
• What is the significance of hair in drug testing?
• What is the fundamental readout of STR typing in capillary electrophoresis?
• What is the difference between autosomal STRs and Y-STRs in terms of inheritance and discrimination?
• Which description matches the Advanced Decay Stage?
• Which of the following is a depressant?
• What is the typical volume of seminal fluid released during ejaculation?
• Why are bone and teeth often targeted in skeletal remains for DNA analysis?
• What is the purpose of luminescence tests in bloodstain detection and what is a common caveat?
• What characteristic of STR loci makes them powerful for distinguishing individuals in a population?
• What is the primary source of narcotics?
• In semen analysis, the acid phosphate test is used to
• Which statement about the sensitivity of forensic protocols is correct?
• What statement best describes mtDNA?
• Why is cross-contamination risk a critical concern in DNA analysis and how is it minimized?
• What is the typical length range for human spermatozoa in microns?
• What is the role of a negative and a positive control in PCR-based DNA testing?
• What is allele dropout and allele dropout risk in low-template samples?
• What is a practical reason to use inhibitor removal resins in DNA extraction?
• Which substance is commonly used to treat opioid addiction and acts on opioid receptors?
• What is the role of qualitative information in drug identification?
• In rifling, what do the terms lands and grooves describe?
• What is taphonomy in forensic science?
• What method is commonly used to determine if a stain is human or non-human DNA?
• How many ossification centers do humans have?
• Which characteristics are used to link bullets to a firearm?
• What is low-copy-number (LCN) DNA and what interpretation challenge does it create?
• What are toolmarks?
• What do antigens on red blood cells determine?
• What is the current legal BAC limit for driving in the US and Canada?
• Explain a challenge in interpreting two-person DNA mixtures and one strategy to address it?
• Which DNA extraction method is generally faster and automation-friendly?
• What is the difference between cortical bone and spongy bone?
• How does capillary electrophoresis readout differ from traditional gel electrophoresis readout?
• Which role do reference family or maternal lineages play in identifying remains?
• What is the purpose of comparing bullet markings?
• Which statement best describes the advantage of MPS over traditional STR methods?
• Which statement accurately describes methadone?
• What is the postmortem interval (PMI) defined as?
• What is the role of primer residue on hands?
• Active Decay Stage includes which of the following?
• Primer residue on hands is evidence of what activity?
• Name a core set of autosomal STR loci commonly used in forensic DNA profiling (e.g., CODIS) and why this set is standardized?
• What is multiplexing in DNA analysis?
• What does minPMI represent?
• What is the Minimum Post Mortem Interval (minPMI)?
• What precautions should be taken when collecting biological evidence?
• What does the Rh factor indicate?
• What effect does DNA degradation have on STR analysis, and what strategy improves results?
• Which of the following is not listed as influencing decomposition?
• What is the role of inhibition controls in qPCR-based DNA testing?
• What does gas chromatography do?
• The Kastle-Meyer test is used for
• What is the purpose of color tests in drug screening?
• Define an STR and explain why STRs are highly informative for human identification?
• Which statement best describes a key advantage of probabilistic genotyping for interpreting mixtures?
• What factor helps maximize DNA recovery from bone during extraction?
• Which test determines whether blood is of human or animal origin?
• Which statement describes a nonspecific preliminary drug test?
• In drug testing, environmental exposure can affect hair analysis by doing what?
• What does Blood Alcohol Concentration (BAC) measure?
• Which option lists the chemical most responsible for marijuana's psychoactive effects?
• Which statement is true about temperature and insect development?
• What does ISO/IEC 17025 accreditation imply for a forensic DNA laboratory?
• Which statement defines Rh-positive status?
• Which of the following is NOT a factor affecting the rate of alcohol absorption?
• What describes antemortem, perimortem, and postmortem trauma?
• Which blood type has B antigens and anti-A antibodies?
• What is the fluid portion of blood called?
• Which blood type has A antigens and anti-B antibodies?
• Describe two common DNA extraction methods and one key advantage of each?
• Which pelvic characteristics are typical of female sex determination?
• What material is recommended for casting shoe impressions?
• Which molecular or immunological methods can rapidly indicate a blood stain's human origin, and what is a common limitation?
• What is the amelogenin gene used for, and what caveat should be considered?
• Which marker can unequivocally identify the presence of semen when positive?
• In a sample containing mixed male and female DNA, which type of marker is most useful to identify the male contributor while mitigating the female background?
• What is the purpose of a presumptive test for blood, and name a common example?
• What is the second method for determining Post Mortem Interval?
• What is a common reason to report a degradation index in forensic DNA testing?
• Why is chain of custody important in forensic biology, and what information is typically recorded?
• What happens in the precipitin test when human blood is injected into an animal?
• Why are STR markers commonly used in forensic analysis?
• What is mitochondrial DNA (mtDNA)?
• STR repeat units typically range in size from
• Among hallucinogens, which is most widely used?
• What is the significance of stutter in STR profiles and how is it addressed during interpretation?
• What are tandem repeats in the human genome?
• What is the purpose of an immunoassay in forensic biology?
• Why is mtDNA typing particularly useful in skeletal remains analysis when nuclear DNA is limited?
• Which statement best describes the combination of evidence in skeletal remains identification to support presumptive conclusions?
• Which statement is NOT a withdrawal symptom of physical dependence?
• What is the purpose of probabilistic genotyping in mixture interpretation?
• Agglutination in blood typing is best described as
• What is crack cocaine?
• Name two confirmatory tests used to identify human blood and briefly describe how they work?
• What is forensic toxicology?
• Chromatography in drug analysis is used to do what?
• What does inter-laboratory reproducibility ensure for forensic DNA results?
• What are Short Tandem Repeats (STRs)?
• Why do laboratories model expected stutter percent by locus?
• Which organization developed CODIS?
• Which stage follows the Active Decay Stage?
• How are acidic drugs extracted from a solution?
• In drug identification, what is the purpose of screening tests?
• Which combination of cranial characteristics is commonly used to identify male skulls?
• What is a stochastic threshold in STR interpretation and why is it important?
• How can sex be identified using STRs?
• What is the significance of environmental exposure in drug testing?
• What is mass spectrometry used for in drug identification?
• How are mixed DNA samples interpreted, and what is allele dropout?
• What indicates a positive acid phosphate test?
• Which statement best describes the relationship between gas chromatography and mass spectrometry in drug identification?
• Which DNA type is commonly used when nuclear DNA is unrecoverable due to degradation, and why?
• Which stage follows the Fresh Stage and precedes Active Decay?