UGC NET Forensic Science: Fingerprints, Fingerprint Identification, Tyre Marks and Biometrics — 30 MCQs with Explanations
Section A: Fingerprints (Q1–Q8)
Q1. Which of the following statements regarding fingerprint patterns is CORRECT?
A. All loop patterns contain two deltas.
B. Plain arches generally lack both a core and a delta.
C. All whorl patterns contain exactly one delta.
D. Tented arches always contain two deltas.
Correct Answer: B. Plain arches generally lack both a core and a delta.
Explanation: Plain arch ridges enter from one side, rise slightly in the centre, and exit from the opposite side. They generally lack a distinct core and delta. Loops typically have one delta, while whorls generally have two or more deltas, depending on the pattern classification.
Q2. In fingerprint examination, the presence of a bifurcation refers to:
A. The termination of a friction ridge
B. The division of one friction ridge into two ridges
C. The merging of two independent fingerprint impressions
D. The formation of a circular ridge pattern
Correct Answer: B. The division of one friction ridge into two ridges.
Explanation: A bifurcation occurs when a single friction ridge divides into two branches. It is a Level 2 fingerprint characteristic, also called a minutia. A ridge ending, by contrast, occurs when a ridge terminates.
Q3. Which of the following is correctly matched with its fingerprint characteristic level?
A. Level 1 — Ridge endings and bifurcations
B. Level 2 — General ridge flow and pattern type
C. Level 3 — Pore structure and ridge edge shapes
D. Level 1 — Sweat pore positions and ridge contours
Correct Answer: C. Level 3 — Pore structure and ridge edge shapes.
Explanation: Fingerprint characteristics are commonly divided into three levels:
- Level 1: General ridge flow and pattern type, such as loops, whorls and arches.
- Level 2: Ridge paths and minutiae, including ridge endings and bifurcations.
- Level 3: Fine ridge details, including pore structure, ridge edge shapes and ridge dimensions.
Q4. Which of the following statements about fingerprint individuality is MOST scientifically appropriate?
A. Every individual has a unique number of ridges on each finger.
B. Fingerprints are considered individualised solely by their pattern classification.
C. Individualisation requires an assessment of the quality, quantity, and spatial relationships of the observed ridge details.
D. Two fingerprints with the same core and delta positions must originate from the same finger.
Correct Answer: C. Individualisation requires an assessment of the quality, quantity, and spatial relationships of the observed ridge details.
Explanation: Fingerprint examination involves evaluating the available ridge detail, its quality, quantity, spatial arrangement and any unexplained differences. A general pattern classification or matching core and delta positions alone cannot establish that two impressions originated from the same finger.
Q5. Which fingerprint pattern is characterised by ridges entering from one side, forming a recurve, and exiting on the same side?
A. Plain arch
B. Loop
C. Plain whorl
D. Accidental whorl
Correct Answer: B. Loop.
Explanation: In a loop pattern, ridges enter from one side, recurve and exit from the same side. Loops generally contain one delta and one core. They are commonly classified as radial loops or ulnar loops according to the direction in which they open.
Q6. In fingerprint classification, the Henry system primarily uses which feature for its primary classification?
A. Number of ridge endings
B. Presence or absence of whorl patterns across the fingers
C. Sweat pore distribution
D. Relative positions of ridge endings and bifurcations
Correct Answer: B. Presence or absence of whorl patterns across the fingers.
Explanation: The primary classification of the Henry system is based on the distribution of whorl patterns across the ten fingers. Numerical values are assigned to finger pairs, and the values of fingers bearing whorls are used to calculate the primary classification fraction. It is a classification system, not a method of individualisation by itself.
Q7. Which of the following is the MOST appropriate interpretation of ridge density in forensic examination?
A. It provides an infallible method of determining sex.
B. It can be influenced by factors such as the finger area examined and the measurement method.
C. It is identical across all fingers of an individual.
D. It is sufficient by itself to individualise a fingerprint.
Correct Answer: B. It can be influenced by factors such as the finger area examined and the measurement method.
Explanation: Ridge density refers to the number of friction ridges within a defined area. Its measured value depends on the region examined, image quality and measurement procedure. Although ridge density has been studied in relation to sex estimation and population differences, it should not be used alone to determine sex or individualise a fingerprint.
Q8. Which condition is most likely to affect the quality of a latent fingerprint without necessarily changing the underlying friction ridge arrangement?
A. Deposition pressure and movement during contact
B. Permanent destruction of the basal epidermal layer
C. Deep scarring that alters the ridge structure
D. Surgical removal of the friction ridge-bearing skin
Correct Answer: A. Deposition pressure and movement during contact.
Explanation: Excessive pressure, insufficient pressure, lateral movement and smearing can distort the appearance of a deposited fingerprint. These factors affect the quality of the impression without necessarily changing the underlying friction ridge arrangement. Deep injuries that damage the regenerative layers of the skin may cause permanent changes to ridge patterns.
Section B: Fingerprint Identification and Development (Q9–Q16)
Q9. Which of the following correctly describes the primary chemical reaction involved in ninhydrin fingerprint development?
A. Reaction with triglycerides to produce a fluorescent product
B. Reaction with amino acids to produce a coloured product, commonly Ruhemann's purple
C. Reaction with sodium chloride to produce a black precipitate
D. Reaction with DNA to produce violet fluorescence
Correct Answer: B. Reaction with amino acids to produce a coloured product, commonly Ruhemann's purple.
Explanation: Ninhydrin reacts with amino acids present in fingerprint residue to produce a characteristic purple-coloured compound known as Ruhemann's purple. It is particularly useful for developing latent fingerprints on porous materials such as paper.
Q10. Which sequence is generally most appropriate when processing an untreated, suspected latent fingerprint on porous paper?
A. Ninhydrin treatment followed by immediate washing with water
B. Appropriate photography and documentation, followed by a suitable chemical development method
C. Cyanoacrylate fuming followed by immersion in concentrated acid
D. Powdering followed by vigorous brushing before initial documentation
Correct Answer: B. Appropriate photography and documentation, followed by a suitable chemical development method.
Explanation: Evidence should be documented before processing whenever practicable. The examiner then selects an appropriate development method based on the substrate, condition of the item and applicable laboratory procedures. Ninhydrin and other amino-acid reagents may be suitable for porous materials. Processing sequences should follow validated protocols because some treatments can affect subsequent examinations.
Q11. Cyanoacrylate fuming develops latent fingerprints primarily through:
A. Oxidation of amino acids into coloured compounds
B. Polymerisation of cyanoacrylate on components associated with fingerprint residue
C. Reduction of chloride ions to metallic silver
D. Direct amplification of DNA in sweat residue
Correct Answer: B. Polymerisation of cyanoacrylate on components associated with fingerprint residue.
Explanation: Cyanoacrylate vapour polymerises on and around components associated with latent fingerprint deposits, producing a whitish polymer that follows the ridge detail. The technique is particularly useful for non-porous surfaces, including glass and certain plastics. Fluorescent dyes may subsequently improve visualisation under suitable illumination.
Q12. Which statement best distinguishes a latent fingerprint from a patent fingerprint?
A. A latent fingerprint is always invisible, whereas a patent fingerprint is always permanent.
B. A latent fingerprint is generally not readily visible, whereas a patent fingerprint is visible because of the material transferred.
C. A latent fingerprint occurs only on porous surfaces.
D. A patent fingerprint must be three-dimensional.
Correct Answer: B. A latent fingerprint is generally not readily visible, whereas a patent fingerprint is visible because of the material transferred.
Explanation: Latent fingerprints are usually not readily visible and often require enhancement. Patent fingerprints are visible because a substance such as blood, ink or grease has been transferred to a surface. Plastic fingerprints are three-dimensional impressions formed when friction ridge skin presses into a deformable material such as wax or soft putty.
Q13. In the ACE-V methodology, the principal purpose of the verification stage is to:
A. Determine the chemical composition of fingerprint residue
B. Independently assess the comparison conclusion
C. Establish the age of the fingerprint
D. Determine the exact time of deposition
Correct Answer: B. Independently assess the comparison conclusion.
Explanation: ACE-V stands for Analysis, Comparison, Evaluation and Verification.
- Analysis: Assess the questioned impression's suitability and characteristics.
- Comparison: Compare questioned and known impressions.
- Evaluation: Assess the significance of the similarities and differences.
- Verification: A second qualified examiner independently reviews the conclusion, according to the laboratory's procedures.
Fingerprint examination does not ordinarily establish the exact time at which a print was deposited.
Q14. Which of the following is a major limitation of an Automated Fingerprint Identification System (AFIS)?
A. It cannot store digitised fingerprint images.
B. It generates candidate lists that require examination and assessment by a qualified examiner.
C. It can process only visible fingerprints and not rolled prints.
D. It automatically establishes the source of every latent print with absolute certainty.
Correct Answer: B. It generates candidate lists that require examination and assessment by a qualified examiner.
Explanation: AFIS uses computer algorithms to search fingerprint databases and generate possible matches. The system ranks candidates according to similarity, but image quality, distortion and incomplete ridge detail can affect results. The candidate list is not, by itself, a definitive identification.
Q15. Which of the following statements concerning fingerprint examination is CORRECT?
A. A fixed minimum number of matching minutiae is universally mandated by forensic science standards worldwide.
B. A high number of corresponding ridge details automatically eliminates the need to evaluate discrepancies.
C. The significance of corresponding ridge details must be evaluated in the context of their quality, quantity, spatial relationships, and any unexplained differences.
D. Similarity in general pattern type alone is sufficient for individualisation.
Correct Answer: C. The significance of corresponding ridge details must be evaluated in context.
Explanation: Fingerprint examination requires an assessment of the totality of the available evidence. There is no universally mandated numerical minimum of matching minutiae that applies to all fingerprint examinations worldwide. The examiner must consider the quality and quantity of detail, its spatial relationships, distortion and any unexplained differences.
Q16. A latent fingerprint on a non-porous surface has been treated with cyanoacrylate fuming. Which subsequent treatment may improve the visibility of developed ridge detail?
A. Fluorescent dye staining, where appropriate
B. Ninhydrin applied indiscriminately without considering the substrate
C. Concentrated hydrochloric acid treatment
D. Complete removal of the polymerised deposit
Correct Answer: A. Fluorescent dye staining, where appropriate.
Explanation: Following cyanoacrylate fuming, a suitable fluorescent dye may be applied to enhance the contrast of developed ridge detail. The treated surface can then be examined using an appropriate light source and viewing filter. The dye and illumination method must be selected according to the surface and the processing protocol.
Section C: Tyre Marks and Tyre Impression Evidence (Q17–Q23)
Q17. Which of the following features is generally most useful for distinguishing a particular tyre from other tyres of the same make and model?
A. Manufacturer's logo alone
B. General tread design alone
C. Randomly acquired cuts, wear, and other individualising characteristics
D. Nominal tyre diameter alone
Correct Answer: C. Randomly acquired cuts, wear, and other individualising characteristics.
Explanation: Tyre evidence contains both class characteristics and potentially individualising characteristics.
- Class characteristics: Tread design, size and manufacturer's pattern.
- Individual characteristics: Random cuts, abrasions, embedded objects and distinctive wear.
A combination of sufficiently detailed corresponding features may support an assessment of whether a questioned impression could have originated from a particular tyre.
Q18. A tyre leaves an impression in soft soil. The impression displays depth variation corresponding to tread blocks. This evidence is best classified as:
A. A two-dimensional patent impression
B. A three-dimensional impression
C. A biological impression
D. A chemical transfer mark
Correct Answer: B. A three-dimensional impression.
Explanation: A three-dimensional impression forms when a tyre presses into a deformable surface, such as mud, sand or soft soil. The impression may preserve tread design, dimensions and some wear or damage characteristics. A tyre mark formed by transferring dust or another material onto a hard surface is generally a two-dimensional impression.
Q19. Which combination of procedures is MOST appropriate for documenting a three-dimensional tyre impression at a crime scene?
A. Immediate casting without photography
B. Overall and close-up photography with a scale, documentation of orientation, and casting when suitable
C. Washing the impression before recording its dimensions
D. Measuring only the total track length without recording tread detail
Correct Answer: B. Overall and close-up photography with a scale, documentation of orientation, and casting when suitable.
Explanation: Proper documentation should preserve both the overall context and the fine details of the impression. Photographs should include a scale placed appropriately in the plane of the impression. When suitable, a cast can preserve the three-dimensional tread features for subsequent examination. The impression should be protected from disturbance before documentation.
Q20. Two tyre impressions exhibit the same general tread design. Which conclusion is scientifically justified?
A. Both impressions must have been produced by the same tyre.
B. The impressions must have originated from vehicles with the same registration number.
C. The general tread design may be consistent with the same tyre model, but further comparison is required to assess a possible common source.
D. The impressions cannot be compared because tread patterns are never useful in forensic examinations.
Correct Answer: C. The general tread design may be consistent with the same tyre model, but further comparison is required.
Explanation: Many tyres share the same commercial tread design. Therefore, a general pattern match usually establishes compatibility with a class of tyres rather than identifying a particular tyre. Individualising features, such as distinctive cuts and wear, may provide additional information.
Q21. Which factor can complicate the interpretation of tyre track width at a crime scene?
A. The vehicle's paint colour
B. Steering angle, tyre deformation, and the nature of the impression
C. The driver's blood group
D. The vehicle's headlamp wattage
Correct Answer: B. Steering angle, tyre deformation, and the nature of the impression.
Explanation: Measured track width may be affected by the vehicle's steering position, tyre deformation, the angle of travel and the characteristics of the ground. Impression distortion can also make the boundaries difficult to determine. Investigators should therefore avoid relying on a single measurement to identify a vehicle.
Q22. A tyre track shows a repeated tread pattern along its length. What is the MOST appropriate inference?
A. The repetition alone conclusively identifies a specific tyre.
B. The repeated pattern may help assess tread design and the continuity of the impression, but does not alone establish individual identity.
C. The track necessarily proves that the vehicle was travelling at a constant speed.
D. The track establishes the exact make and registration number of the vehicle.
Correct Answer: B. The repeated pattern may help assess tread design and continuity, but does not alone establish individual identity.
Explanation: Repeated tread elements can assist in identifying the tread design and understanding how the impression was produced. However, multiple tyres may produce the same pattern. Repetition alone cannot establish the identity of a particular tyre, vehicle or driver, nor does it prove that the vehicle maintained a constant speed.
Q23. Which of the following is the principal forensic value of comparing questioned tyre impressions with known test impressions?
A. Determining the driver's age
B. Assessing similarities and differences in class and individual characteristics
C. Establishing the exact time of the incident from tread depth alone
D. Determining the chemical composition of the road surface
Correct Answer: B. Assessing similarities and differences in class and individual characteristics.
Explanation: Known test impressions can be produced from a suspect tyre under controlled conditions and compared with questioned impressions. The examiner assesses tread design, dimensions, wear and other corresponding features while accounting for differences caused by pressure, surface conditions and distortion.
Section D: Biometrics and Biometric Identification (Q24–Q30)
Q24. Which of the following biometric characteristics is generally considered behavioural rather than physiological?
A. Iris pattern
B. Fingerprint ridge arrangement
C. Gait
D. Retinal vascular pattern
Correct Answer: C. Gait.
Explanation: Physiological biometrics are based on anatomical or physical characteristics, such as fingerprints, iris patterns and retinal vascular patterns. Behavioural biometrics are based on actions or patterns of behaviour, including gait, signature dynamics and keystroke dynamics. Gait may be influenced by clothing, injury, walking surface and speed.
Q25. Which statement correctly distinguishes iris recognition from retinal recognition?
A. Iris recognition analyses the coloured ring around the pupil, whereas retinal recognition analyses vascular patterns at the back of the eye.
B. Iris recognition analyses the retina, whereas retinal recognition analyses the cornea.
C. Both systems analyse exactly the same anatomical structure.
D. Retinal recognition is based exclusively on pupil diameter.
Correct Answer: A. Iris recognition analyses the coloured ring around the pupil, whereas retinal recognition analyses vascular patterns at the back of the eye.
Explanation: Iris recognition uses the distinctive patterns in the iris, the coloured structure surrounding the pupil. Retinal recognition examines the vascular pattern of the retina at the back of the eye. These are different anatomical structures and require different acquisition methods.
Q26. In biometric authentication, the Equal Error Rate (EER) is the point at which:
A. False Acceptance Rate and False Rejection Rate are equal
B. Genuine Acceptance Rate and False Acceptance Rate are equal in every system
C. All genuine users are rejected
D. The system stops comparing biometric templates
Correct Answer: A. False Acceptance Rate and False Rejection Rate are equal.
Explanation: The Equal Error Rate is the operating point at which the False Acceptance Rate (FAR) equals the False Rejection Rate (FRR).
- FAR: The rate at which unauthorised users are incorrectly accepted.
- FRR: The rate at which legitimate users are incorrectly rejected.
A lower EER generally indicates better biometric discrimination when systems are evaluated under comparable conditions. However, operational performance also depends on the chosen threshold and application requirements.
Q27. A biometric system has a high False Acceptance Rate (FAR). What does this indicate?
A. Genuine users are frequently rejected.
B. Impostors are accepted as genuine users more frequently than desired.
C. The system cannot enrol any users.
D. All biometric samples are classified as invalid.
Correct Answer: B. Impostors are accepted as genuine users more frequently than desired.
Explanation: A high FAR indicates that the system incorrectly accepts a relatively high proportion of impostor attempts. This presents a security concern, particularly in access-control systems. Tightening the matching threshold may reduce FAR but can increase FRR, meaning more genuine users may be rejected.
Q28. Which of the following best describes a biometric template?
A. A complete copy of a person's entire biological identity
B. A digital representation of selected features extracted from a biometric sample for comparison
C. A person's government-issued identity document
D. A permanent record that can never be compromised or misused
Correct Answer: B. A digital representation of selected features extracted from a biometric sample for comparison.
Explanation: A biometric template is a digital representation of relevant features extracted from a biometric sample, such as a fingerprint image or facial image. The system compares the template with another template or a stored reference. Templates are not necessarily complete copies of the original biometric sample, but they still require appropriate security and privacy safeguards.
Q29. Why can multimodal biometric systems offer advantages over unimodal systems?
A. They eliminate all false matches.
B. They combine information from multiple biometric sources, potentially improving discrimination and robustness.
C. They do not require enrolment.
D. They guarantee accurate identification under all environmental conditions.
Correct Answer: B. They combine information from multiple biometric sources, potentially improving discrimination and robustness.
Explanation: A multimodal biometric system combines two or more biometric characteristics, such as fingerprints and facial recognition or fingerprints and iris recognition. Combining modalities may improve reliability, reduce dependence on a single biometric source and help address certain acquisition failures. However, multimodal systems do not eliminate all errors and still require appropriate security controls.
Q30. Which statement about biometric identification and verification is CORRECT?
A. Identification generally involves a one-to-many search, whereas verification generally involves a one-to-one comparison against a claimed identity.
B. Identification always involves a one-to-one comparison, whereas verification is always one-to-many.
C. Both identification and verification necessarily require DNA analysis.
D. Verification determines a person's identity without comparing biometric data.
Correct Answer: A. Identification generally involves a one-to-many search, whereas verification generally involves a one-to-one comparison against a claimed identity.
Explanation:
- Identification (1:N): The system compares a person's biometric sample against multiple enrolled templates to determine whether a matching identity exists.
- Verification (1:1): The system compares the person's biometric sample against the template associated with the identity they claim.
For example, searching a fingerprint against a large database is an identification task, while checking a fingerprint against a registered user's stored template to unlock a device is a verification task.
0 Comments