UGC NTA NET/JRF Exam, Forensic Science, June-2025

Total Questions: 100

31. Any document completely written and signed by one person, is known as:

Correct Answer: 2. Holograph
Solution:

A holograph (holographic document) is entirely written and signed by the same person. It's distinct from a hologram (optical image) and an exemplar (specimen writing collected for comparison).

32. Arrange the following steps in correct order for performing a competitive solid phase radioimmunoassay to measure cytokine level:

A. Coat the RIA plate with anti cytokine antibody.
B. Add a constant amount of 1251 labeled cytokine to all wells.
C. Add increasing concentration of unlabeled cytokine to generate a standard curve.
D. Add experimental samples to separate wells.
E. Measure radioactivity and determine cytokine concentrations by comparing with the standard curve.
Choose the correct answer from the options given below:

Correct Answer: 3. A, B, C, D, E
Solution:

Competitive solid-phase RIA workflow: coat plate with anti-cytokine antibody (A) → add a constant amount of radio-labeled cytokine (B) → add increasing unlabeled cytokine to build the standard curve (C) → add unknown samples to separate wells (D) → measure bound radioactivity and read concentrations from the standard curve (E).

33. Rigor mortis sets up due to chemical changes involving ________ and indicates the molecular death of its cells.

Correct Answer: 1. Structural proteins of the muscle fibers
Solution:

Rigor mortis follows post-mortem ATP depletion, locking actin and myosin (muscle structural proteins) into stable actomyosin cross-bridges.

Calcium contributes to contraction, but the hallmark rigidity stems from protein complex fixation when ATP is unavailable.

34. Evidence is information provided through:

A. Artificial Intelligence
B. Testimony
C. Documentation
D. Hearsay
Choose the correct answer from the options given below:

Correct Answer: 2. B, C only
Solution:

Legally recognized evidence is conveyed through witness testimony (B) and documentary/real records (C). Hearsay (D) is generally inadmissible except for limited exceptions, and "AI" (A) is not itself a recognized evidentiary mode.

35. In a case of death due to suspected poisoning by carbon monoxide, which sample should be preserved without adding any preservative?

Correct Answer: 2. Blood
Solution:

For suspected carbon monoxide poisoning, blood-kept airtight and filled to the brimis preserved without additives to accurately quantify carboxyhaemoglobin.
Preservatives are unnecessary here and other tissues are less reliable for COHb estimation.

36. Match List-I with List-II:

List-I (Fiber)List-II (Obtained From)
A. CottonI. Fruit
B. CoirII. Leaf
C. FlaxIII. Seed
D. ManilaIV. Stem

Choose the correct answer from the options given below:

Correct Answer: 2. A-III, B-I, C-IV, D-II
Solution:

Fibres are classified based on their origin in plants. Cotton is a seed fibre, produced from the seed hairs of Gossypium, and is one of the world's most important textile fibres (III).

Coir is a fruit fibre, obtained from the fibrous mesocarp (husk) of coconut fruit, mainly used for mats, ropes, and brushes (I).

Flax is a stem or bast fibre, taken from the inner bark of the flax plant's stem, used to make linen (IV). Manila hemp or abacá is a leaf fibre, derived from the leaf sheaths of Musa textilis (a banana species), prized for making ropes and speciality papers (II).

37. In low voltage electrophoresis, which of the following characteristics are normally observed?

A. Longer run time
B. Increased risk of sample degeneration
C. Better separation of large molecules
D. Low heat generation
Choose the correct answer from the options given below: 

Correct Answer: 4. A, D only
Solution:

In electrophoresis, the applied voltage controls migration speed and heat generation. At low voltage, the weaker electric field slows molecular migration, producing a longer run time (А).

Because heat generated is proportional to the square of voltage, lower voltage causes low heat generation (D), protecting sensitive samples like proteins or nucleic acids. Low voltage does not increase degeneration; in fact, it reduces thermal damage.

Better separation of large molecules depends mainly on gel pore size and buffer systems, not simply low voltage.

38. The time of ossification from bones gives a good indication of age but few points are to be remembered before giving an opinion, like:

A. Variation due to diet
B. Union of epiphysis in cartilaginous bones
C. Tropical conditions are not considered
D. Genotyping from bones
Choose the correct answer from the options given below:

Correct Answer: 4. А, В only
Solution:

Using ossification to estimate age requires careful consideration of biological and environmental factors. Nutritional variation (A), such as calcium or vitamin D deficiency, can delay ossification, while good diet can accelerate it.

Epiphyseal union in cartilaginous bones (B) occurs at predictable ages, and its presence or absence is a key forensic marker in adolescents and young adults.

The statement that tropical conditions are "not considered" is wrong-climatic and genetic factors are always considered. Genotyping (D) helps with personal identification but is unrelated to ossification timing.

39. Arrange the following in the correct sequence of paper-making process.

A. Bleaching and beating
B. Drying and calendaring
C. Cooking and blowing under pressure
D. Refining and sending on Fourdrinier wire
Choose the correct answer from the options given below:

Correct Answer: 1. C, A, D, B
Solution:

The paper-making process is stepwise: first, cooking and blowing under pressure (C) treats raw material (like wood chips) with chemicals to break down lignin and release cellulose fibres, producing pulp.

Then comes bleaching and beating (A), where fibres are whitened and mechanically beaten to improve bonding. Next, refining and sending on Fourdrinier wire (D) forms a continuous wet sheet as the pulp slurry is spread on a moving mesh.

Finally, drying and calendaring (B) removes moisture and passes the sheet through rollers, giving smoothness, gloss, and the required thickness.

40. Excimer lasers are created through the recombination of noble gases and halogens. Select the correct noble gas which is paired with fluorine to obtain excimer lasers.

Correct Answer: 2. Xenon
Solution:

Excimer lasers are ultraviolet lasers formed from an excited dimer of a noble gas and a halogen. The most common example is xenon fluoride (XeF).

Xenon, when combined with fluorine in an excited state, produces intense ultraviolet emission, widely used in semiconductor photolithography, LASIK eye surgery, and microfabrication.

Helium and neon form other types of lasers (like He-Ne), but not excimer lasers with fluorine. Radon is radioactive and unsuitable. Hence, xenon is the correct noble gas paired with fluorine for excimer laser production.