Personal Identification Methods — MCQs
Which of the following statements best describes a key characteristic of fingerprint development?
What is the forensic method of identification that utilizes lip prints?
Which banding technique is most commonly used for karyotyping?
Which of the following is the least suitable source for DNA extraction?
What is the most reliable criterion for selecting teeth in prosthodontics?
During a postmortem examination of a young adult found with a faded tattoo, relatives mentioned that the tattoo was once visible. What is the best method to identify the tattoo?
At what age does a child typically know their full name?
What is the best investigation for identifying malaria species?
Four weeks after assisting in several calf deliveries, a farmer develops fever, weakness, muscle aches, and sweats. The fever rises in the afternoon and falls during the night. A Brucella species is isolated. Which Brucella species is a possible bioterrorism agent and is best described by one of the following?
The cephalic index is used for the determination of what?
Personal Identification Methods Indian Medical PG Practice Questions and MCQs
Question 1: Which of the following statements best describes a key characteristic of fingerprint development?
- A. Fingerprints are fully formed before birth. (Correct Answer)
- B. DNA analysis is the most specific method of identification.
- C. The most common type of fingerprint is loops.
- D. None of the options are true.
Explanation: ***Fingerprints are fully formed before birth.*** - Fingerprints begin to develop during the **fetal stage**, specifically between the 10th and 17th weeks of gestation. - Once formed, their unique ridge patterns remain **unchanged throughout life**, except for changes due to injury or disease. *DNA analysis is the most specific method of identification.* - While **DNA analysis** is a highly specific method of identification, the statement refers to its specificity generally, not as a characteristic of fingerprint development itself. - Fingerprints are a distinct form of identification based on unique **dermal ridge patterns**, independent of genetic material. *The most common type of fingerprint is loops.* - It is true that **loops** are indeed the most common type of fingerprint pattern, occurring in about 60-70% of the population. - However, this statement describes a characteristic of fingerprint patterns, not a key characteristic of their **development** or formation. *None of the options are true.* - This option is incorrect because the statement that **fingerprints are fully formed before birth** is a key characteristic of fingerprint development. - This option would only be correct if all other statements were false.
Question 2: What is the forensic method of identification that utilizes lip prints?
- A. Trichology
- B. Dactylography
- C. Poroscopy
- D. Cheiloscopy (Correct Answer)
Explanation: ***Cheiloscopy*** - **Cheiloscopy** is the scientific study of lip prints for human identification, based on the unique patterns of furrows on the human lips. - These patterns are considered individual and permanent, making them useful in forensic investigations. *Dactylography* - **Dactylography** is the study of fingerprints, which involves analyzing the unique patterns of ridges and furrows on the fingertips for identification. - It is one of the most widely used and reliable methods for personal identification in forensic science, but does not involve lip prints, *Poroscopy* - **Poroscopy** is a forensic technique that involves the examination of the pores on the ridges of fingerprints. - It is used to individualize fingerprints when there is insufficient ridge detail, but it focuses on pores, not lip prints. *Trichology* - **Trichology** is the scientific study of hair and scalp. - In forensics, it involves analyzing hair samples to determine characteristics such as origin, race, and presence of toxins, but not lip prints.
Question 3: Which banding technique is most commonly used for karyotyping?
- A. G banding (Correct Answer)
- B. Q banding
- C. C banding
- D. R banding
Explanation: ***G banding*** - This method is the **most widely used** technique for karyotyping, allowing clear visualization of chromosome bands under light microscopy [1][2]. - G banding helps in identifying **chromosomal abnormalities** and is routinely utilized in clinical genetics [2]. *C banding* - Primarily highlights the **centromeric regions** of chromosomes, but is less common than G banding for overall karyotyping. - Does not provide a full **karyotype view**, making it less suitable for routine analysis. *R banding* - Useful for providing **reverse staining**, which shows the bands in a different manner but is not as commonly employed in clinical settings. - Typically used to analyze specific **chromosomal translocations**, rather than routine karyotyping. *Q banding* - This technique involves **fluorescent microscopy** to visualize chromosomes but is not as prevalent for basic karyotyping. - Mainly used for detecting **specific chromosomal anomalies**, not the standard karyotype assessment. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 54-55. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Genetic Disorders, pp. 167-168.
Question 4: Which of the following is the least suitable source for DNA extraction?
- A. CSF (Correct Answer)
- B. Hair roots
- C. Semen
- D. Buccal mucosa
Explanation: ***CSF*** - **Cerebrospinal fluid (CSF)** contains a relatively **low number of cells**, making it a poor source for DNA extraction compared to other bodily fluids due to the scarcity of nuclear DNA. - While DNA can be extracted from CSF for specific diagnostic purposes (e.g., detection of pathogens), it is generally **not the preferred source** for DNA profiling or genetic studies due to the limited yield and potential for degradation. *Hair roots* - **Hair roots** (specifically the follicular tag) contain a significant number of **nucleated cells**, making them an excellent source for DNA extraction. - The DNA extracted from hair roots is often robust and sufficient for **forensic analysis** and genetic testing. *Semen* - **Semen** contains a high concentration of **sperm cells**, which are rich in nuclear DNA, making it a very good source for DNA extraction. - It is frequently used in **forensic investigations** and paternity testing due to its high DNA content. *Buccal mucosa* - **Buccal cells** scraped from the inside of the cheek provide a non-invasive and **abundant source of nucleated cells** for DNA extraction. - This method is widely used for genetic testing, **ancestry tracing**, and clinical diagnostics because of its ease of collection and high DNA yield.
Question 5: What is the most reliable criterion for selecting teeth in prosthodontics?
- A. Radiographic analysis.
- B. Clinical assessment.
- C. Patient's functional needs.
- D. All of the options. (Correct Answer)
Explanation: ***All of the options.*** - The selection of teeth in prosthodontics requires a **holistic approach**, integrating various diagnostic tools and patient-specific factors to ensure optimal esthetics, function, and longevity of the restoration. - Relying on a single criterion would lead to an incomplete assessment and potentially compromise the success of the prosthetic treatment. *Clinical assessment.* - **Clinical assessment** provides crucial information about the existing dentition, including tooth morphology, periodontal health, occlusal relationships, and available restorative space. - However, relying solely on clinical assessment may miss underlying issues not visible clinically, such as periapical pathology or bone defects. *Radiographic analysis.* - **Radiographic analysis** offers valuable insights into the internal structure of teeth, bone support, root morphology, and the presence of underlying pathology like caries or periapical lesions. - While essential, radiographs do not fully convey the patient's functional demands, esthetic expectations, or dynamic occlusal relationships. *Patient's functional needs.* - Understanding the **patient's functional needs** is paramount for selecting teeth that can withstand masticatory forces, contribute to proper speech, and allow for comfortable oral hygiene. - Focusing only on functional needs without considering the biological constraints or esthetic desires would lead to restorations that might be biomechanically sound but displeasing or impractical for the patient.
Question 6: During a postmortem examination of a young adult found with a faded tattoo, relatives mentioned that the tattoo was once visible. What is the best method to identify the tattoo?
- A. Use a spectrophotometer for analysis
- B. Illuminate with ordinary light
- C. Perform an X-ray examination
- D. Illuminate with ultraviolet (UV) light (Correct Answer)
Explanation: ***Illuminate with ultraviolet (UV) light*** - **UV light** causes residual tattoo pigments, even faded ones, to **fluoresce**, making them visible again for identification. - This method is particularly effective for **older or faded tattoos** where the pigment has degraded or spread. *Use a spectrophotometer for analysis* - A spectrophotometer is used to measure the **intensity of light** as a function of wavelength, which is useful for **analyzing chemical components or color intensity**. - While it can analyze pigments, it is not the primary or most practical method for merely **identifying the presence and pattern of a faded tattoo** on skin, especially in a postmortem context. *Illuminate with ordinary light* - **Ordinary visible light** is typically insufficient to reveal tattoos that have significantly faded or been subjected to processes that obscure them. - If the tattoo is already faded to the point of being invisible to the naked eye, **ordinary light will not enhance its visibility** as it lacks the specific wavelengths needed to cause fluorescence. *Perform an X-ray examination* - **X-rays** are used to visualize dense structures like **bones and foreign bodies**, not for examining skin or pigments. - Tattoo pigments are generally **not radiopaque** and would not be visible on an X-ray film, rendering this method useless for tattoo identification.
Question 7: At what age does a child typically know their full name?
- A. 15 months
- B. 24 months
- C. 36 months (Correct Answer)
- D. 48 months
Explanation: ***36 months*** - By **36 months old** (3 years), most children can clearly state their **full name** (first and last name) when asked. - This milestone indicates developing **self-awareness** and **language skills**. - This is a standard developmental milestone tested in CDC and AAP guidelines. *15 months* - At **15 months**, children typically know their **first name** and respond to it, but cannot state their full name. - Their language at this age often includes only a few single words with primarily receptive understanding. *24 months* - By **24 months** (2 years), children often use two-to-four-word sentences and can identify familiar objects and people. - While they know their first name and may start recognizing it, they usually cannot articulate their full name yet. *48 months* - At **48 months** (4 years), a child's language skills are much more advanced, and they can typically tell stories and engage in complex conversations. - Knowing their full name is an expected milestone that should have been achieved earlier, typically by 36 months.
Question 8: What is the best investigation for identifying malaria species?
- A. Thick smear
- B. Thin smear with Giemsa (Correct Answer)
- C. QBC
- D. Thin smear with acridine orange
Explanation: ***Thin smear with Giemsa*** - A **thin smear** allows for the visualization of **parasite morphology** within red blood cells, which is crucial for distinguishing between species of *Plasmodium*. - **Giemsa stain** provides optimal contrast for identifying characteristic features such as **merozoites**, **trophozoites**, **schizonts**, and **gametocytes** of different malaria species. *Thick smear* - A **thick smear** is primarily used for **detecting the presence of malaria parasites** and for quantifying parasite density due to its higher sensitivity. - However, because red blood cells are lysed, it **does not preserve parasite morphology** well, making species identification difficult. *QBC* - **Quantitative Buffy Coat (QBC) analysis** is a rapid method for detecting malaria parasites based on their fluorescence under UV light. - While sensitive for detection, it generally **does not allow for precise species identification** due to the lack of clear morphological detail. *Thin smear with acridine orange* - A **thin smear stained with acridine orange** is used for rapid detection of parasites by fluorescence microscopy. - Similar to QBC, it is **less effective for detailed morphological examination** and specific species identification compared to Giemsa-stained thin smears.
Question 9: Four weeks after assisting in several calf deliveries, a farmer develops fever, weakness, muscle aches, and sweats. The fever rises in the afternoon and falls during the night. A Brucella species is isolated. Which Brucella species is a possible bioterrorism agent and is best described by one of the following?
- A. Typically infects goats and sheep, grows well in CO2, and is not inhibited by thionine or basic fuchsin dyes (Correct Answer)
- B. Commonly inhabits the canine respiratory tract and is an occasional pathogen for humans; strongly urease-positive
- C. Gram-negative bipolar stained bacilli that cause diarrhea by means of a heat-stable enterotoxin, with abdominal pain that may be mistaken for appendicitis
- D. Pits agar, grows both in carbon dioxide and under anaerobic conditions, and is part of the normal oral cavity flora
Explanation: ***Typically infects goats and sheep, grows well in CO2, and is not inhibited by thionine or basic fuchsin dyes*** - This description is characteristic of ***Brucella melitensis***, which is recognized as the most pathogenic **Brucella** species and a potential **bioterrorism agent** (CDC Category B) due to its high infectivity and severe disease course. - Its specific growth requirements (CO2 preference) and dye resistance patterns (not inhibited by **thionine** or **basic fuchsin**) are key laboratory identifiers that differentiate it from other **Brucella** species (*B. abortus* is inhibited by thionine; *B. suis* is inhibited by basic fuchsin). - Low infective dose (10-100 organisms) and aerosol transmission capability make it a significant bioterrorism threat. *Commonly inhabits the canine respiratory tract and is an occasional pathogen for humans; strongly urease-positive* - This describes ***Bordetella bronchiseptica***, not a **Brucella** species. It is a pathogen primarily associated with animals, especially dogs (kennel cough), and only rarely causes disease in immunocompromised humans. - While it can be urease-positive, it belongs to a different genus and does not fit the clinical or epidemiological context of brucellosis. *Gram-negative bipolar stained bacilli that cause diarrhea by means of a heat-stable enterotoxin, with abdominal pain that may be mistaken for appendicitis* - This description points to ***Yersinia enterocolitica***, not a **Brucella** species. It is a **Gram-negative bacterium** known for causing gastrointestinal infections with symptoms that can mimic **appendicitis** (pseudoappendicitis syndrome). - Its characteristic **bipolar staining** ("safety pin" appearance) and production of **heat-stable enterotoxin** are distinct from **Brucella** species. *Pits agar, grows both in carbon dioxide and under anaerobic conditions, and is part of the normal oral cavity flora* - This description is typical of ***Eikenella corrodens***, not a **Brucella** species. It is a **Gram-negative bacillus** found in the **normal oral flora** that can cause infections related to human bites or dental procedures. - Its ability to "pit" agar and specific atmospheric growth requirements (CO2 and anaerobic) are unique characteristics that differentiate it from **Brucella** species.
Question 10: The cephalic index is used for the determination of what?
- A. Sex
- B. Race (Correct Answer)
- C. Height
- D. Stature
Explanation: **Explanation:** The **Cephalic Index (CI)**, also known as the Index of Retzius, is a primary anthropometric tool used in forensic medicine to determine **Race** (Option B). It expresses the ratio of the maximum breadth of the skull to its maximum length. **Formula:** $$\text{Cephalic Index} = \frac{\text{Maximum Breadth of Skull}}{\text{Maximum Length of Skull}} \times 100$$ Based on this index, human races are categorized into three main groups: 1. **Dolichocephalic (Long-headed):** CI < 75. Characteristic of **Aryans, Africans (Negroids), and Aborigines**. 2. **Mesaticephalic (Medium-headed):** CI 75–80. Characteristic of **Europeans and Chinese**. 3. **Brachycephalic (Short/Broad-headed):** CI > 80. Characteristic of **Mongoloids**. **Why other options are incorrect:** * **Sex (A):** While the skull exhibits sexual dimorphism (e.g., supraorbital ridges, mastoid process), the Cephalic Index is not a reliable indicator of sex. * **Height/Stature (C & D):** Stature is estimated using the **Ponderal Index** or by applying **Karl Pearson’s formula** to long bones (like the Femur or Humerus), not the skull dimensions. **High-Yield NEET-PG Pearls:** * **Vertical Index:** Used to determine race based on the height of the skull relative to its length. * **Nasal Index:** Another high-yield parameter for race; **Leptorrhine** (narrow nose) is typical of Caucasians, while **Platyrrhine** (broad nose) is typical of Africans. * **Mixed Race:** In India, the average population is generally **Mesaticephalic**. * **Forisic Tip:** If only the skull is provided, the **Cephalic Index** is the most reliable method for racial identification.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free