Tag: Assistant Professor certification

Answer: C. Combination of impression and striated marks

Explanation: When a plier or a similar tool is used to loosen a tight knob, the jaws of the tool can leave a combination of impression marks (from the pressure exerted) and striated marks (from the gripping and twisting action). The combination of these two types of marks is characteristic of the action of pliers or wrenches on tight knobs or surfaces.

Answer: D. All of the above

Explanation: When matching and comparing layers of paint samples, various factors can provide valuable information. Surface discoloration, changes in tint due to weathering, and layers of dirt can all contribute to the analysis and comparison of paint samples. These factors can help in determining the age, environmental exposure, and other characteristics of the paint samples, which can be crucial in forensic investigations.

Answer: C. Angle of progression

Explanation: The spacing between striations caused by a tool with a thin cutting edge is primarily influenced by the angle of progression, which is the angle at which the tool is moved across the surface. A steeper angle of progression will result in closer spacing between striations, while a shallower angle will lead to wider spacing. The nature of the tool’s teeth, the angle of tilt, and the relative hardness of the tool and surface can also affect the striations but have a lesser impact on the spacing between them.

Answer: C. China

Explanation: India Ink, a type of ink commonly used in calligraphy, drawing, and writing, was invented in ancient China. It is a carbon-based ink made from a mixture of carbon black, water, and a binding agent. The name “India Ink” is a misnomer, as it originated in China and was later brought to Europe through trade routes, where it was mistakenly associated with India.

Answer: A. makes it more stable to rapid temperature changes

Explanation: Adding boron to molten glass improves its thermal shock resistance, making it more stable to rapid temperature changes. Boron acts as a flux in the glass melt, lowering the viscosity and allowing for better workability. It also helps to strengthen the glass structure, making it more resistant to cracking or shattering due to sudden temperature fluctuations.

Answer: B. Feces

Explanation: Skatole is a byproduct of the breakdown of tryptophan, an amino acid present in proteins, by intestinal bacteria. It is primarily responsible for the characteristic odor associated with feces. Skatole is produced in the human digestive system and contributes to the distinct fecal odor, making it a characteristic odor of feces.

Answer: A. Roots

Explanation: The roots of hair are the preferred part used for DNA typing and establishing identity. The root portion of the hair contains the hair follicle, which is rich in cellular material and nucleated cells. These cells contain intact DNA, making the root portion ideal for DNA extraction and analysis. The cuticles, medulla, and other parts of the hair shaft do not contain nucleated cells and are less suitable for DNA typing.

Answer: D. Precipitins

Explanation: When human serum is injected into an animal, the animal’s immune system recognizes the human proteins as foreign and produces antibodies called precipitins. Precipitins are a type of antibody that can form insoluble complexes with the corresponding antigen, leading to precipitation. This property of precipitins is used in various forensic and serological tests, such as identifying species-specific blood or other bodily fluids.

Answer: B. Keratin

Explanation: As the hair follicles reach the top of the skin, the outer layer of the hair begins to harden into a fibrous protein called keratin. Keratin is the primary structural component of hair, nails, and the outermost layer of the skin. It is a tough and insoluble protein that provides strength and protection to these structures. The hardening of the outer layer of the hair into keratin is a crucial step in the formation of the hair shaft.

Answer: D. Acidulated water

Explanation: In the soaking method for analyzing seminal stains, the stained area is cut and soaked in acidulated water. Acidulated water is water that has been made slightly acidic, typically by the addition of a mild acid like acetic acid or hydrochloric acid. This acidic environment helps to extract and dissolve the seminal components, such as proteins and enzymes, from the stain, allowing for further analysis and testing.

Answer: B. No carbon required

Explanation: In questioned document examination, the term “NCR” stands for “No Carbon Required.” It refers to a type of paper that produces a copy without the need for a carbon sheet or transfer film. NCR paper is coated with a microencapsulated dye or ink, which is released when pressure is applied, creating a duplicate copy. This technology eliminated the need for carbon paper in creating multiple copies of documents.

Answer: D. Ruhemann’s purple

Explanation: The formation of the final purple-colored product resulting from the reaction between amino acids and ninhydrin is known as Ruhemann’s purple. This reaction is widely used in forensic science and biochemistry to detect and visualize latent fingerprints or other traces of amino acids on porous surfaces like paper or fibers. The formation of Ruhemann’s purple is a characteristic of the ninhydrin reaction and is used as a confirmatory test for the presence of amino acids.

Answer: B. It bleeds writings

Explanation: The ninhydrin method is preferred for developing latent fingerprints on porous surfaces like paper. However, it is not recommended for use on paper with ballpoint pen writings because the ninhydrin reagent can cause the ink to bleed or spread, potentially obscuring or distorting the written text. This phenomenon, known as “bleeding,” occurs due to the interaction between the ninhydrin solution and the ink components, leading to the ink spreading and making the writings illegible.

Answer: D. Projectina Universal

Explanation: The Projectina Universal is a specialized instrument used in questioned document examination for the physical matching of torn pieces of paper. It utilizes a combination of transmitted and oblique lighting techniques to enhance and visualize the unique characteristics of the paper edges, such as fiber patterns, tears, and other distinctive features. By carefully aligning and matching these features, forensic document examiners can determine if two or more torn paper fragments originated from the same larger document.

Answer: A. 1024

Explanation: In the primary classification of fingerprints, there are 1024 classes. This classification system is based on the patterns formed by the ridges on the fingertips, known as the “ridge pattern types.” The primary classification divides fingerprints into four main categories: loops, whorls, arches, and composite patterns. Each of these categories is further subdivided into subclasses based on specific ridge characteristics, resulting in a total of 1024 possible classes.

Answer: C. 50 cms

Explanation: At full term, which is typically around 40 weeks of gestation, the average length of a human fetus is approximately 50 centimeters (cm) or 19.7 inches. This length is measured from the top of the head to the heel, also known as the crown-to-heel length. The length can vary slightly, but 50 cm is considered the average length for a full-term newborn baby.

Answer: A. Nuclear sexing

Explanation: Barr and Bertram are associated with nuclear sexing, a technique used to determine the biological sex of an individual based on the presence or absence of the Barr body (also known as the sex chromatin) in cell nuclei. The Barr body is a condensed, inactivated X chromosome found in female somatic cells. This technique was developed by Murray Barr and Keith Bertram in the late 1940s and is widely used in forensic investigations, particularly in cases involving skeletal remains or body fluids.

Answer: C. Stature

Explanation: Karl Pearson’s formula, also known as the Pearson’s linear regression formula, is commonly used in forensic anthropology to estimate the stature (height) of an individual based on the measurements of long bones, such as the femur or humerus. This formula establishes a mathematical relationship between the length of the bone and the stature, taking into account factors like sex, ancestry, and population-specific data. It is a widely accepted method for reconstructing the approximate height of an individual from skeletal remains.

Answer: A. Race

Explanation: The ratio of the length and breadth of the skull, known as the cranial index, is used in forensic anthropology to help determine the race or ancestry of an individual. Different racial groups tend to exhibit distinct patterns and variations in the shape and proportions of the skull. For example, individuals of European descent generally have longer and narrower skulls (dolichocephalic), while those of Asian descent often have broader and shorter skulls (brachycephalic). By analyzing the cranial index, forensic anthropologists can gain insights into the potential racial or ancestral affiliation of skeletal remains.

Answer: D. No time limit

Explanation: In India, there is no specific time limit prescribed for the exhumation (digging up and removal) of buried bodies or remains. The decision to exhume a body is made on a case-by-case basis by the relevant authorities, such as the police or the judiciary, based on the circumstances and requirements of the investigation or legal proceedings. While exhumations are generally carried out as soon as possible after burial to ensure better preservation of evidence, there is no legal time restriction on when an exhumation can be conducted in India.

Answer: D. (ii) (iv) (i) (iii)

Explanation: The color changes in blood can provide valuable information about the cause of death or the presence of certain substances. The correct matching between the color changes and their causative factors is as follows:
(a) Cherry red color – (i) Cyanide poisoning
(b) Reddish purple color – (iv) Usual post-mortem changes
(c) Bright red color – (ii) Carbon monoxide poisoning
(d) Chocolate brown color – (iii) Potassium chlorate poisoning

Answer: C. Skull

Explanation: The frontal sinus is a pair of air-filled cavities located within the frontal bone of the skull, just above the eyes. The structure and configuration of the frontal sinus are unique to each individual, even among identical twins, making it a valuable feature for personal identification in forensic investigations. The unique pattern of the frontal sinus can be used for positive identification by comparing ante-mortem (before death) radiographs or CT scans with post-mortem (after death) skeletal remains.

Answer: D. Somatometric measurements

Explanation: Somatometric measurements, which involve measuring various physical characteristics of the body, such as height, weight, and limb proportions, cannot provide positive identification on their own. While these measurements can help narrow down the search or provide supporting evidence, they are not unique enough to establish positive identification definitively. In contrast, dental records, fingerprints, and DNA profiling are considered reliable methods for positive identification due to their unique and individualistic nature.

Answer: C. To perform autopsy

Explanation: Performing autopsies is not one of the primary objectives of forensic anthropology. Forensic anthropologists are primarily concerned with the analysis and interpretation of skeletal remains and other physical evidence related to the human body. Their main objectives include field recovery (locating and recovering human remains), establishing a biological profile (estimating age, sex, ancestry, stature, etc.), and identifying trauma or other evidence relevant to the manner of death. However, conducting autopsies, which involve the examination of internal organs and tissues, falls within the domain of forensic pathologists or medical examiners.

Answer: B. Tattoo

Explanation: Tattoos are not useful for determining personal identification from skeletal remains alone. While tattoos can be valuable in identifying individuals when soft tissues are present, they do not leave any permanent marks or evidence on bones. Dentition (dental records), bone disorders (such as pathological conditions or congenital anomalies), and surgical implants (like prosthetic joints or plates) can provide valuable information for personal identification from skeletal remains, as they leave distinctive markers or characteristics that can be analyzed and compared with ante-mortem records.

Answer: A. 2-7%

Explanation: Cooking gas, which is typically a mixture of propane and butane, forms an explosive mixture with air when the concentration of the gas falls within the range of 2-7% by volume. This range is known as the explosive range or the flammable range. Outside this range, the mixture is either too lean (insufficient fuel) or too rich (insufficient oxygen) to support an explosion. Understanding the explosive range of cooking gas is crucial for safety measures and preventing potential accidents or explosions.

Answer: C. (iv) (iii) (i) (ii)

Explanation: In forensic and material science, understanding the origin and characteristics of fibers is crucial. Wool, categorized as an animal fiber, is made from the fleece of sheep and other animals. It has crimps or waves, which trap air and make it an excellent insulator. Nylon is a synthetic fiber created through a chemical process, known for its strength and elasticity. Cotton, derived from the cotton plant’s seed pod, is a plant fiber cherished for its softness and breathability. Asbestos is a mineral fiber, historically used for its resistance to heat and electrical conductivity but is now less common due to its health risks, including lung diseases and cancer.

Answer: D. None of the above

Explanation: A ball cartridge fired from a rifle is not loaded with any of the options mentioned. A ball cartridge, also known as a ball ammunition or a ball round, typically contains a full metal jacket bullet with a cylindrical or ogival shape. It is designed for general-purpose use and does not have any specialized features like armor-piercing capabilities or incendiary effects. The term “ball” refers to the basic, standard ammunition used in rifles or other firearms.

Answer: A. d = (π/θ) tan l

Explanation: In the case of a rifled barrel, the angle of rifling (θ), the pitch of rifling (l), and the caliber of the rifle (d) are related by the equation d = (π/θ) tan l. The pitch of rifling is the distance traveled by the bullet in one complete revolution inside the barrel, and the angle of rifling is the angle at which the rifling grooves are cut into the barrel. The caliber is the internal diameter of the barrel. This relationship helps in determining the optimal combination of rifling parameters for a given caliber, ensuring accurate and stable bullet flight.

Answer: A. more than that of 12-bore gun

Explanation: In shotguns and other smooth-bore firearms, the bore size is typically expressed in terms of the gauge or bore number. The bore number indicates the number of lead balls of that diameter that make up a pound. A lower bore number corresponds to a larger internal diameter of the barrel. Therefore, a 10-bore gun has a larger internal cross-sectional diameter than a 12-bore gun, which in turn has a larger diameter than a 20-bore gun. The 8-bore gun has an even larger diameter than the 10-bore gun.

Answer: A. Inhalation

Explanation: Crack, also known as crack cocaine, is a freebase form of cocaine that is typically smoked or inhaled. The process of heating and inhaling the vapors from crack cocaine is known as “freebasing” or “smoking crack.” Crack is a highly potent and addictive substance, and inhalation is the primary route of abuse due to the rapid onset of its effects when the vapors are absorbed through the lungs.

Answer: C. Meprobamate

Explanation: Meprobamate is a central nervous system (CNS) depressant drug belonging to the class of carbamate compounds. It was historically used as an anxiolytic (anti-anxiety) and sedative medication but has been largely replaced by safer alternatives due to its potential for abuse and dependence. CNS depressants like meprobamate slow down brain activity, producing sedative and calming effects. Methcathinone, ecgonine, and methylphenidate are stimulants that have the opposite effect, increasing brain activity and producing a heightened state of alertness or euphoria.

Answer: D. Ammonium molybdate test

Explanation: The ammonium molybdate test is a recommended screening test for the detection of organophosphorous compounds, which include various pesticides, insecticides, and nerve agents. This test involves the formation of a blue complex when organophosphorous compounds react with ammonium molybdate in the presence of hydrogen peroxide. The intensity of the blue color can provide an indication of the presence and concentration of these compounds. Other tests like Marquis’, Fraehde’s, and Husemann’s tests are primarily used for the detection of different classes of drugs or compounds.

Answer: B. Methaqualone

Explanation: The main active ingredient in Mandrax, a sedative-hypnotic drug, is methaqualone. Methaqualone is a central nervous system (CNS) depressant that belongs to the quinazolinone class of drugs. Mandrax tablets were widely abused for their sedative and euphoric effects, particularly in the 1960s and 1970s, before being made illegal in many countries due to their high potential for abuse and addiction. Meprobamate, methaamphetamine, and methylphenidate are different drugs with different effects and applications.

Answer: A. Secobarbital

Explanation: Secobarbital, a barbiturate derivative, is known by the street name “Red Devils” due to the red color of the capsules or tablets containing this drug. Secobarbital is a central nervous system (CNS) depressant that was previously used as a sedative and hypnotic medication but has been largely replaced by safer alternatives due to its high potential for abuse and dependence. The term “Red Devils” refers specifically to the red-colored secobarbital capsules or tablets that were commonly abused for their sedative and euphoric effects.

Answer: C. T-A

Explanation: In the double-stranded structure of DNA, the complementary base-pairing follows the pattern of Adenine (A) pairing with Thymine (T), and Guanine (G) pairing with Cytosine (C). This specific base-pairing is known as complementary base-pairing, and it is the foundation of the DNA double helix structure. The correct complementary base pair is T-A, where the Thymine base on one strand pairs with the Adenine base on the complementary strand through hydrogen bonding.

Answer: C. Cut DNA at specific sites

Explanation: In the Restriction Fragment Length Polymorphism (RFLP) technique, restriction enzymes play a crucial role by cutting DNA molecules at specific recognition sequences. These enzymes are endonucleases that recognize and cleave double-stranded DNA at specific nucleotide sequences, resulting in DNA fragments of varying lengths. The ability of restriction enzymes to precisely cut DNA at specific sites is essential for the RFLP technique, which involves analyzing the resulting fragment patterns to identify genetic variations or polymorphisms.

Answer: D. Enamel

Explanation: For blood-grouping using the absorption-elution technique, the enamel portion of teeth is not preferred. The absorption-elution technique involves absorbing blood group antigens onto the tooth surface and then eluting (extracting) them for analysis. Enamel, being the hardest and most mineralized part of the tooth, does not absorb antigens as effectively as other tooth tissues. The dental pulp, cementum, and dentin are better suited for this technique as they can more readily absorb and retain blood group antigens.

Answer: C. Both monoclonal and polyclonal antibodies

Explanation: The immunological test strips used to confirm the presence of human blood typically contain a combination of both monoclonal and polyclonal antibodies. Monoclonal antibodies are highly specific and target a single epitope (binding site) on the target antigen, while polyclonal antibodies can recognize multiple epitopes on the same antigen. By incorporating both types of antibodies, the test strips can provide higher sensitivity and specificity in detecting human blood, reducing the chances of false positives or false negatives.

Answer: B. Oswald Avery

Explanation: Oswald Avery, an American scientist, is credited with defining the role of DNA as the vehicle for the generational transfer of heritable traits. In 1944, Avery and his colleagues conducted a groundbreaking experiment that demonstrated that DNA, and not proteins, carried the genetic instructions that could transform the properties of bacteria. This discovery laid the foundation for understanding DNA as the hereditary material and paved the way for further advancements in molecular genetics and DNA profiling techniques.

Answer: B. The secondary and back-scattered electrons

Explanation: In a Scanning Electron Microscope (SEM), the magnified image of a particle or sample is formed by the detection of secondary and back-scattered electrons. When the primary electron beam from the SEM interacts with the sample, it causes the emission of secondary electrons from the sample surface and the reflection of back-scattered electrons from the sample. These secondary and back-scattered electrons are collected and processed to generate the magnified image, providing detailed information about the sample’s topography and composition.

Answer: B. Decreasing λ, increasing both n and α

Explanation: To increase the resolving power (R) of an objective lens, the following conditions should be met: 1. Decrease the wavelength of light (λ) used for illumination. Shorter wavelengths allow for higher resolution. 2. Increase the refractive index (n) of the object space. A higher refractive index allows for a wider angle of acceptance and higher numerical aperture. 3. Increase the half-angle (α) of the outermost rays entering the lens. A larger angle of acceptance increases the numerical aperture and improves resolution. By decreasing the wavelength (λ) and increasing both the refractive index (n) and the half-angle (α), the resolving power (R) of the objective lens can be maximized according to the given formula.

Answer: D. Inversely proportional to √V

Explanation: According to the de Broglie relationship, the wavelength (λ) of waves associated with electrons accelerated through a potential difference of V volts is inversely proportional to the square root of the potential difference (√V). This relationship is given by the equation: λ = (h/√(2meV)) Where: h is the Planck constant m is the mass of the electron e is the charge of the electron As the potential difference (V) increases, the electrons gain more kinetic energy, and their associated wavelength decreases, following an inverse square root relationship.

Answer: C. are emitted when a beam of primary electrons strike the object.

Explanation: In a Scanning Electron Microscope (SEM), secondary electrons are emitted from the sample surface when the beam of primary electrons strikes the object or specimen. The primary electrons interact with the atoms in the sample, causing the ejection of loosely bound electrons from the sample surface. These ejected electrons, known as secondary electrons, are then detected and used to generate the magnified image of the sample’s surface topography and composition.

Answer: A. Isotropic

Explanation: A substance that behaves in the same way to light polarized in any direction is said to be isotropic. Isotropic materials have uniform physical properties in all directions, meaning their optical, mechanical, or other properties are the same regardless of the direction of observation or measurement. Examples of isotropic substances include liquids, gases, and amorphous solids like glass. In contrast, anisotropic substances exhibit different properties depending on the direction, such as crystals or materials with a preferred orientation of molecules or structures.

Answer: D. Hostile witness

Explanation: During an examination-in-chief, which is the questioning of a witness by the party that called them, leading questions are generally not allowed. However, an exception is made for hostile witnesses, as they are considered uncooperative or biased against the party calling them. In such cases, the court may permit the use of leading questions to elicit relevant information from a hostile witness during the examination-in-chief. Leading questions are questions that suggest the desired answer or contain the answer within the question itself.

Answer: D. High

Explanation: The High Court is an appellate court in the judicial system. An appellate court is a court that has the authority to review decisions and judgments made by lower courts and to either affirm, modify, or reverse those decisions. The High Court serves as an appellate court for cases appealed from lower courts, such as District and Sessions Courts or subordinate courts. It has the power to review and revise the judgments and orders of the lower courts within its jurisdiction.

Answer: B. Perjury

Explanation: Making false statements under oath amounts to the criminal offense of perjury. Perjury is the intentional act of swearing a false oath or falsifying evidence while under oath, either verbally or in writing. It is considered a serious offense as it undermines the integrity of the judicial system and the administration of justice. Perjury can lead to legal consequences, including fines or imprisonment, depending on the jurisdiction and the severity of the offense.

Answer: A. S. 45

Explanation: In Indian courts, DNA fingerprinting evidence has been accepted as admissible evidence under Section 45 of the Indian Evidence Act, 1872. Section 45 deals with the opinion of expert witnesses and states that when the court has to form an opinion upon a point of foreign law, or of science, or art, or as to the identity of handwriting or fingerprints, the opinions of persons specially skilled in such matters are relevant facts. DNA fingerprinting, being a scientific technique, falls under the purview of Section 45, allowing expert opinions and analysis to be presented as evidence in legal proceedings.

Answer: Wrong question.

Explanation: The question itself seems to be incorrectly stated or ambiguous, as the options provided do not match the given list items correctly. The list items refer to specific sections of the Indian Penal Code (IPC) related to sexual offenses, but the options do not align with the stated sections. Without a clear understanding of the context or the specific legal provisions being referenced, it is difficult to provide an accurate explanation for this question.

Answer: B. Kolkata Central Forensic Science Lab.

Explanation: DNA typing, also known as DNA profiling or DNA fingerprinting, is a crucial forensic technique used to identify individuals based on their unique genetic makeup. In India, the first facility for DNA typing in a forensic science laboratory was introduced at the Kolkata Central Forensic Science Lab. This lab played a pioneering role in establishing DNA analysis capabilities for forensic investigations in the country.

Answer: B. Crime Scene Management

Explanation: Tele Forensics Technology is a cutting-edge approach that leverages telecommunication and remote sensing technologies for effective crime scene management. It allows forensic experts to remotely assess and analyze crime scenes, provide guidance, and collaborate with on-site investigators. This technology enhances the efficiency and accuracy of crime scene investigations, particularly in cases where physical access is challenging or hazardous.

Answer: B. (a) and (c) are correct.

Explanation: The mechanical system of a compound microscope consists of the base, which provides stability and support, and the body tube, which houses the optical components and allows adjustment of the focus. The condenser and illumination are part of the optical system and not the mechanical system of a compound microscope. The base and body tube are the primary mechanical components that enable the proper functioning and positioning of the microscope.

Answer: C. Corpus delicti

Explanation: Corpus delicti is a legal term that refers to the essential facts or elements that prove a crime has been committed. It is crucial in criminal cases to establish the corpus delicti, which includes evidence that a specific crime occurred and that the defendant was involved in committing the crime. Without proving the corpus delicti, a conviction cannot be obtained, even if there is a confession or other circumstantial evidence.

Answer: A. (A) is right, but (R) is wrong.

Explanation: The assertion that the answer in a leading question asked during a trial is given in a yes or no format is correct. Leading questions are designed to elicit specific responses and often suggest the desired answer. However, the reason provided is incorrect. Leading questions are typically not allowed during direct examination (examination-in-chief) of one’s own witness but can be used during cross-examination of the opposing party’s witness.

Answer: D. A photoemissive tube

Explanation: A monochromator is an optical device used to isolate a specific wavelength or narrow range of wavelengths from a broader spectrum of light. It typically consists of an entrance slit, a collimator to produce parallel rays of light, and a grating or prism to disperse the light into its constituent wavelengths. A photoemissive tube, on the other hand, is a detector used to measure the intensity of the selected wavelength and is not a part of the monochromator itself.

Answer: B. Delhi

Explanation: The Central Detective Training Schools in India are located in various cities to provide specialized training to law enforcement personnel in investigation techniques, forensic sciences, and related fields. Among the given options, Delhi does not have a Central Detective Training School. These schools are present in Kolkata, Hyderabad, and Chandigarh, among other locations across the country.

Answer: B. Near-Infrared spectrometry

Explanation: Near-Infrared (NIR) spectrometry is a valuable analytical technique for analyzing mixtures of aromatic amines. Aromatic amines are organic compounds containing an amino group (-NH2) attached to an aromatic ring. NIR spectrometry can differentiate and quantify these compounds based on their characteristic absorption patterns in the near-infrared region of the electromagnetic spectrum. This technique is widely used in various fields, including forensic analysis, for the identification and characterization of aromatic amines and their mixtures.

Answer: C. Triglycerides

Explanation: The Physical developer is a fingerprint development technique used to reveal latent (invisible) fingermarks on porous surfaces like paper, cardboard, or wood. It reacts specifically with the triglyceride components present in sweat residue left behind by the friction ridges of the fingerprint. The reaction between the Physical developer and the triglycerides results in the formation of a dark gray or black deposit, making the fingerprint ridges visible and enhancing their contrast against the background.

Answer: B. (A) is correct, but (R) is incorrect.

Explanation: The assertion that retention time is used for identifying unknown compounds in gas chromatography (GC) is correct. Retention time is a characteristic property of a compound and is determined by its interaction with the stationary phase in the GC column. However, the reason provided is incorrect. Retention time is not the time taken by a compound to travel from the column to the recorder; rather, it is the time taken by a compound to elute (exit) from the column after injection.

Answer: A. (iii) (i) (iv) (ii)

Explanation: The correct matching of detectors with their respective components is as follows: (a) Differential Thermal conductivity detector – (iii) Wheatstone bridge circuit (b) Flame ionization detector – (i) Polarizing electrode (c) Electron capture detector – (iv) Radioactive foil (d) HPLC (High-Performance Liquid Chromatography) – (ii) A refractive index monitor

Answer: D. All of the above

Explanation: SDS-PAGE (Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis) is a widely used analytical technique for separating and analyzing proteins based on their molecular weight. In an SDS-PAGE, all the statements given in the options are true. SDS is a detergent that denatures and unfolds proteins, coating them with a uniform negative charge. This results in all proteins having the same charge-to-mass ratio. Smaller proteins then migrate more rapidly through the polyacrylamide gel due to their lower molecular weight, allowing for their separation and analysis.

Answer: A. 5 – 10 %

Explanation: The AB blood group is the rarest of the four major blood groups (A, B, AB, and O). Its approximate frequency in the general population is around 5-10%. The most common blood group is O, followed by A and B. The AB blood group results from the co-inheritance of the A and B antigens, which is relatively rare in most populations. The specific frequency of the AB blood group can vary slightly among different ethnic groups and geographical regions.

Answer: D. Thermocouples

Explanation: In gas chromatography, various detectors are used to detect and quantify the separated components. TCD (Thermal Conductivity Detector), FID (Flame Ionization Detector), and ECD (Electron Capture Detector) are commonly used detectors for gas chromatography. Thermocouples, on the other hand, are not used as detectors in gas chromatography. Thermocouples are temperature-measuring devices that work on the principle of the thermoelectric effect and are used in various applications but not as detectors in gas chromatography.

Answer: B. Phenolphthalein

Explanation: The Kastle-Meyer presumptive test for the detection of blood is also known as the Phenolphthalein test. This test utilizes the oxidizing properties of the heme component in blood to catalyze the oxidation of phenolphthalein, resulting in a pink or red color change. The presence of this color change indicates a presumptive positive result for the presence of blood. However, it should be noted that this test can produce false positives with certain other oxidizing agents, and further confirmatory tests are often required.

Answer: B. Schizophrenia

Explanation: Schizophrenia is a severe mental disorder characterized by distorted thinking, hallucinations, delusions, and impaired cognitive abilities. It is classified as a psychotic disorder and is not considered a neurosis. Neuroses, on the other hand, are a group of mental disorders characterized by anxiety, fear, obsessive thoughts, and distressing emotions, but without a complete break from reality. Anxiety, hypochondriasis (excessive preoccupation with health concerns), and phobias (irrational fears) are examples of neurotic disorders mentioned in the list.

Answer: C. Both (A) and (R) are incorrect.

Explanation: The assertion that all humans have A antigens in their blood is incorrect. The presence of A antigens on red blood cells determines the A blood group, but not all individuals have these antigens. Similarly, the reason stating that it produces both anti-A and anti-B antibodies is also incorrect. Individuals with the A blood group produce only anti-B antibodies, while those with the B blood group produce only anti-A antibodies. The production of both anti-A and anti-B antibodies occurs in individuals with the O blood group, where neither the A nor B antigens are present.

Answer: A. Probes

Explanation: Short fragments of DNA labeled with radioactive tags or other detectable labels are known as DNA probes. These probes are used in various molecular biology techniques, such as Southern blotting, fluorescence in situ hybridization (FISH), and DNA microarrays, to detect and identify specific sequences of interest within larger DNA samples. The radioactive or fluorescent labels on the probes allow for their visualization and detection when they hybridize or bind to their complementary target sequences.

Answer: A. Hexagonal

Explanation: The Urea Nitrate crystal test is a qualitative analytical method used to detect the presence of urea in urine samples. When urea reacts with nitric acid in this test, it forms hexagonal-shaped crystals of urea nitrate. The formation of these characteristic hexagonal crystals under a microscope is indicative of the presence of urea in the urine sample being tested. This test is often used in forensic and clinical settings for the analysis of urine samples.

Answer: B. (iii) (i) (iv) (ii)

Explanation: The correct matching of poisons with their common names is as follows: (a) Marijuana – (iii) Pot (b) Mescaline – (i) Moons (c) Cocaine – (iv) Crack (d) Heroin – (ii) Smack Marijuana, also known as “pot,” is derived from the cannabis plant and is often used as a recreational drug. Mescaline is a psychedelic compound found in certain cacti, with the common street name “moons.” Cocaine is a highly addictive stimulant drug that is sometimes referred to as “crack” when in its free-base form. Heroin, an opioid drug, is commonly known by the street name “smack.”

Answer: C. C40

Explanation: Furnace oil, also known as black oil, is a heavy fuel oil derived from the fractional distillation of crude oil. It consists primarily of hydrocarbons with carbon chain lengths greater than C40 (containing more than 40 carbon atoms). These longer-chain hydrocarbons have higher boiling points and are less volatile, making them suitable for use as a fuel in industrial furnaces, boilers, and other heavy-duty applications. The composition of furnace oil varies depending on the source and refining process, but it typically contains a complex mixture of aliphatic and aromatic hydrocarbons with carbon numbers ranging from C40 to C70 or higher.

Answer: D. Alcohol dehydrogenase

Explanation: Alcohol dehydrogenase (ADH) is an enzyme primarily found in the liver that catalyzes the oxidation of ethanol (alcohol) to acetaldehyde. This reaction is the first step in the metabolic breakdown of alcohol in the body. Alcohol dehydrogenase requires the cofactor NAD+ (nicotinamide adenine dinucleotide) to carry out this oxidation reaction. The acetaldehyde produced is then further metabolized by another enzyme, aldehyde dehydrogenase (ALDH), into acetic acid, which can be broken down into carbon dioxide and water for elimination from the body.

Answer: C. Synergistic effect

Explanation: The combined use of alcohol and dhatura (a plant containing tropane alkaloids like atropine and scopolamine) can lead to a synergistic effect, where the effects of both substances are amplified or enhanced. Dhatura, known for its anticholinergic properties, can cause delirium, hallucinations, and other adverse effects. When combined with alcohol, which is a central nervous system depressant, the synergistic effect can result in severe impairment, confusion, and potentially life-threatening consequences. This interaction highlights the importance of avoiding the concurrent use of alcohol and substances like dhatura.

Answer: C. (ii) (iii) (i) (iv)

Explanation: The correct matching of paint pigments with their respective colors is as follows: (a) 2PbCo3 · Pb(OH)2 – (ii) White (b) Zinc chromate – (iii) Yellow (c) Ferric ferrocyanide – (i) Blue (d) Impure ferric oxide – (iv) Bluish red to pale red brown These pigments are commonly used in various types of paints and coatings. 2PbCo3 · Pb(OH)2 (lead white) is a white pigment, zinc chromate is a yellow pigment, ferric ferrocyanide (Prussian blue) is a blue pigment, and impure ferric oxide (red oxide) can produce reddish-brown shades.

Answer: A. Both (A) and (R) are correct.

Explanation: Endrin, an organochlorine insecticide, was once widely used in agriculture and is referred to as “Plant Penicillin” due to its broad-spectrum activity against various insect pests and its importance in protecting crops. The assertion that Endrin is called “Plant Penicillin” is correct. The reason provided, stating that Endrin has a broad spectrum of activity against various insects and pests, is also correct. However, it is important to note that Endrin has been banned or severely restricted in many countries due to its high toxicity and environmental persistence.

Answer: B. C = 0.035

Explanation: The ballistics coefficient (C) is a dimensionless number used to describe the ability of a projectile to overcome air resistance during flight. It is a function of various factors, including the projectile’s shape, mass, and diameter. For LG shot, which refers to lead gunshot or shotgun pellets, the typical ballistics coefficient value is approximately C = 0.035. This value reflects the relatively low aerodynamic efficiency of spherical lead projectiles, which experience significant air resistance due to their shape.

Answer: D. (i) (ii) (iii) (iv)

Explanation: The correct chronological order of occurrence for the given firearms is as follows: 1. Match lock guns 2. Flint lock musket 3. Revolver 4. Assault rifle Match lock guns were among the earliest firearms, dating back to the 15th century. They were followed by the development of flint lock muskets in the 17th century. The revolver, a repeating firearm with a rotating cylinder, was invented in the early 19th century. Assault rifles, which are selective-fire rifles capable of automatic or burst fire, emerged in the 20th century.

Answer: A. Suspension of body by a ligature around the neck, body weight acting as constricting force.

Explanation: Hanging is a form of asphyxia caused by the suspension of the body by a ligature around the neck, where the body’s weight acts as the constricting force. This definition accurately captures the key elements of hanging, which involve the use of a ligature (such as a rope or cord) to compress the neck, leading to airway obstruction and ultimately death by asphyxiation. The suspension of the body is crucial, as it allows the body’s weight to tighten the ligature around the neck, constricting the airway and disrupting breathing.

Answer: B. (A) is correct, but (R) is incorrect.

Explanation: The assertion that a questioned bullet and a test bullet can be compared positively using a comparison microscope is correct. Forensic ballistic examiners use comparison microscopes to analyze and compare the unique markings left on fired bullets by the firearm’s barrel and breech surfaces. However, the reason provided is incorrect. The breech block marks on fired bullets are not identical but rather exhibit unique characteristics that can be used for identification purposes. These marks are created by the breech block impacting the base of the cartridge case during firing, leaving distinct impressions that can be compared and matched to a specific firearm.

Answer: C. (a) and (d) are correct.

Explanation: Smokeless powders are propellants used in firearms and ammunition that burn without producing visible smoke. The common forms of smokeless powders are Ballistite and Cordite, which are made up of nitrocellulose and other additives. Ballistite is a double-base powder containing nitrocellulose and nitroglycerin, while Cordite is a triple-base powder containing nitrocellulose, nitroglycerin, and nitroguanidine. Dynamite and blasting gelatine sticks are high explosives used in mining and demolition work, not smokeless powders used in firearms.

Answer: B. Bread hair

Explanation: Bread hair, also known as vellus hair or downy hair, is the fine, short hair that covers most of the human body, except for the palms, soles, and some other areas. Bread hair is characterized by its relatively small diameter and a distinctive triangular cross-sectional shape when viewed under a microscope. This triangular shape helps differentiate bread hair from other types of hair, such as scalp hair (which typically has a circular or oval cross-section) or animal hair, and can be useful in forensic investigations involving hair analysis.

Answer: A. Both (A) and (R) are correct.

Explanation: Both the assertion and the reason are correct in relation to the graying process of hair. Gray hair is characterized by a lack or significant reduction of melanin granules, which are responsible for hair pigmentation. The reason for this is the gradual loss of tyrosinase activity in the hair follicles. Tyrosinase is an enzyme involved in the production of melanin pigments. As people age, the activity of tyrosinase decreases, leading to a reduction in melanin synthesis and, consequently, the appearance of gray or white hair.

Answer: B. Polyvinyl acetate

Explanation: Rayon is a type of synthetic fiber made from regenerated cellulose. The different types of rayon include Cupramonium rayon, Polynosic rayon, and Viscose rayon. These types differ in the specific chemical processes used to produce the regenerated cellulose fibers. However, polyvinyl acetate is not a type of rayon. Polyvinyl acetate is a synthetic polymer made from vinyl acetate monomers and is used in a variety of applications, including adhesives, coatings, and paints, but it is not a form of regenerated cellulose fiber like rayon.

Answer: D. Rate of decrease in speed of a moving vehicle as a brake testing instrument.

Explanation: A decelerometer is an instrument used to measure the rate of deceleration or the rate of decrease in speed of a moving vehicle. It is particularly useful in evaluating the performance of braking systems and determining the effectiveness of brakes in slowing down or stopping a vehicle. Decelerometers are commonly employed in brake testing procedures, where they provide quantitative data on the vehicle’s deceleration rate, which is essential for assessing the braking system’s efficiency and compliance with safety standards.

Answer: D. (a) and (c) are correct.

Explanation: When analyzing walking patterns, protractors and measuring tapes are the most useful instruments. Protractors are used to measure the angles formed by the feet, legs, and other body parts during different phases of the walking cycle. Measuring tapes are essential for determining stride length, step length, and other linear measurements related to the walking pattern. Dividers and scales, while useful in other applications, are not as directly relevant for measuring the parameters of walking patterns.

Answer: B. Electrophoresis

Explanation: Electrophoresis is a technique used to separate charged molecules, such as proteins or nucleic acids, based on their size and charge. It is not commonly used for soil examination. The other methods listed, including the density gradient-tube method, thermo gravimetric method, and spectrographic analysis, are useful techniques for analyzing soil samples. The density gradient-tube method separates soil components based on density differences, the thermo gravimetric method determines the composition of soil by measuring weight changes upon heating, and spectrographic analysis identifies the elemental composition of soil through spectroscopic techniques.

Answer: B. (b) and (d) are correct.

Explanation: Portland cement is a widely used construction material, and its main components are calcium oxide (CaO) and silicon oxide (SiO2). These two compounds, along with smaller amounts of aluminium oxide and iron oxide, are the primary constituents of Portland cement. The calcium oxide and silicon oxide are derived from the calcination of limestone and clay, respectively, during the cement manufacturing process. These components react to form the calcium silicate compounds that give Portland cement its binding and strength properties. Magnesium oxide is not a primary component of Portland cement.

Answer: C. (b) and (d) are correct.

Explanation: Bottle glass, also known as soda-lime glass, is primarily composed of silicon dioxide (SiO2) and calcium oxide (CaO). These two compounds, along with smaller amounts of sodium oxide and other additives, make up the main components of bottle glass. Manganese oxide (MnO) and zinc oxide (ZnO) are not typically present in the composition of bottle glass. MnO is sometimes used as a decolorizer in other types of glass, while ZnO is used in certain specialty glass formulations but not in standard bottle glass.

Answer: B. Bite marks

Explanation: The ABFO (American Board of Forensic Odontology) scale No. 2 is specifically designed for the analysis and documentation of bite marks. Bite marks are patterned injuries caused by the teeth of humans or animals, and their examination falls under the domain of forensic odontology. The ABFO scale No. 2 provides a standardized method for describing the characteristics and features of bite marks, facilitating their comparison and identification. It is not typically used for the analysis of tool marks, finger marks, or other types of impressions or marks.

Answer: B. Crown

Explanation: Enamel is the hard, protective outer layer that covers the crown of the tooth, which is the visible part above the gum line. Enamel is the hardest and most mineralized substance in the human body, consisting of hydroxyapatite crystals. It serves to protect the underlying dentin and pulp from mechanical forces and chemical attacks. Enamel is not present in the root of the tooth, nor is it found in the pulp or dentin layers, which are located beneath the enamel and crown.

Answer: B. Krogman W.M. & Iscan, M.Y.

Explanation: The book “Human Skeleton in Forensic Medicine” was co-authored by Wilton M. Krogman and Mehmet Yaşar Iscan. Krogman was a renowned physical anthropologist, and Iscan is a forensic anthropologist known for his contributions to the field of skeletal analysis. This book is considered a classic reference work in forensic anthropology and skeletal biology, providing comprehensive information on the human skeleton and its applications in forensic investigations and identifications.

Answer: A. 2102/2102

Explanation: The dental formula represents the number and types of teeth present in the primary (deciduous) and permanent dentitions. The dental formula for the primary set of human dentition, also known as the deciduous or milk teeth, is 2102/2102. This formula indicates that in each quadrant of the mouth, there are 2 incisors, 1 canine, and 2 molars, totaling 20 primary teeth. The “/” separates the upper and lower arches, each having the same tooth count and arrangement.

Answer: C. Allometry

Explanation: Allometry refers to the study of the proportional relationship between the size of various body parts and the overall body size or stature. It examines how the relative dimensions of different body components change as the overall size increases or decreases. Allometric principles are widely used in anthropology, forensics, and biology to estimate stature from skeletal remains or other body parts, as well as to understand growth patterns and morphological variations across different species or populations.

Answer: B. 2 years

Explanation: The metopic suture is a fibrous joint that separates the two halves of the frontal bone in the skull during early childhood. It typically fuses or closes by the age of 2 years in most individuals. The closure of the metopic suture is an important developmental milestone and is often used as a reference point in forensic anthropology and pediatric cranial assessments. In some cases, the metopic suture may persist beyond 2 years of age, but this is considered a variation rather than the norm.

Answer: D. All of the above

Explanation: Albert S. Osborn is considered a pioneer in the field of questioned document examination. He authored several influential works, including “Questioned Documents,” “The Problem of Proof,” and “Questioned Document Problems.” These books laid the foundation for modern questioned document examination techniques and principles, covering various aspects such as handwriting analysis, typewriting identification, ink and paper analysis, and the examination of erasures and alterations. Osborn’s contributions significantly advanced the field of forensic document examination and are widely recognized in the forensic science community.

Answer: C. Amino acids

Explanation: Indanedione is a chemical reagent used in forensic science to develop latent (invisible) fingerprints on porous surfaces like paper, cardboard, or untreated wood. It reacts with the amino acid components present in the sweat residue left behind by the friction ridges of a fingerprint. This reaction produces a fluorescent product that highlights the fingerprint ridges, making them visible under an appropriate light source. While sweat residue contains other components like urea, sodium chloride, and fatty acids, it is the amino acids that specifically react with Indanedione to develop latent fingermarks.

Answer: D. Hard evidence

Explanation: Cyanoacrylate, also known as “super glue,” is widely used in forensic science for developing latent fingerprints on non-porous surfaces like glass, metal, or plastic. When cyanoacrylate is in a gel form, it is commercially referred to as “Hard evidence.” This gel formulation allows for easier application and better adhesion to various surfaces, enabling the visualization of fingerprints through the polymerization process. The “Hard evidence” term distinguishes it from the conventional liquid cyanoacrylate formulations used for fuming purposes.

Answer: D. All of the above

Explanation: When collecting standards for comparison in forensic document examination, several factors are crucial to ensure accurate and reliable analysis. Contemporaneousness of writing refers to the standards being produced around the same time as the questioned document, accounting for any potential changes in handwriting over time. Similarity of the contents of the writing helps ensure that the standards represent the same writing style and conditions as the questioned document. Additionally, a sufficient amount of writing is necessary to capture natural variations and provide an adequate sample for comparison. All of these factors are important considerations when collecting appropriate standards for forensic handwriting or document analysis.

Answer: B. Second level details

Explanation: In the study of fingerprints, Galton’s details refer to the specific ridge characteristics or minutiae that make each fingerprint unique. These details are also known as second-level details or ridge details. Examples of Galton’s details include bifurcations (ridge splits), ridge endings, dots, and other minor ridge formations. These second-level details, along with the overall pattern type (first-level detail) and pores and edge contours (third-level details), form the basis of fingerprint identification and individualization in forensic science.

Answer: B. Both (A) and (R) are correct.

Explanation: The assertion that an exact superimposition of one’s handwriting is an indication of traced forgery is correct. In forensic document examination, when two handwritten samples are perfectly superimposed, it suggests that one sample was likely traced or copied from the other, rather than being naturally written. This is because natural handwriting exhibits variations due to factors such as muscle movement, writing position, and pen pressure. The reason provided is also correct. It is expected that two handwriting samples from the same individual will differ to some extent due to the presence of natural variations. Even when a person tries to replicate their own handwriting, there will be slight differences in letter formations, slant, spacing, and other features. This concept of natural variation is a fundamental principle in handwriting analysis and forgery detection.

Answer: B. Di-anion

Explanation: The Luminol test is a forensic technique used to detect trace amounts of blood at crime scenes. Luminol (3-aminophthalhydrazide) is a chemical compound that reacts with the iron present in the heme component of hemoglobin, producing a bluish-green chemiluminescence. In this reaction, luminol reacts with an oxidizing agent (such as hydrogen peroxide) in the presence of a catalyst (such as a blood salt), forming a di-anion. This di-anion then decomposes, releasing energy in the form of light, thereby revealing the presence of blood.

Answer: D. Urea

Explanation: Para-dimethylaminocinnamaldehyde (DMAC) is a chemical reagent used in forensic investigations to detect the presence of urea. When DMAC reacts with urea, it produces a pink-colored product. Urea is a waste product excreted in urine and is also present in other biological fluids like blood and sweat. The formation of the pink color is a positive indication of the presence of urea, which can assist in identifying and analyzing biological stains or traces at crime scenes.

Answer: C. (A) is correct and (R) is incorrect.

Explanation: The corporo-basal index, also known as the cranial index, is a method used in forensic anthropology to determine the sex of an individual from skeletal remains, particularly the skull. It is calculated by dividing the maximum breadth of the skull by the maximum length of the skull and multiplying by 100. However, the reason (R) is incorrect because the corporo-basal index is not derived from the measurements of individual bones of the skull but rather the overall dimensions of the skull.

Answer: D. Fusion of Xiphisternum and manubrium

Explanation: The fusion of the xiphisternum (the smallest and cartilaginous part of the sternum) and the manubrium (the upper broad part of the sternum) is the last skeletal change to occur among the options provided. This fusion typically occurs in late adulthood or old age, usually after the age of 60. The other skeletal changes, such as the fusion of the metopic suture, the fusion of the greater cornu of the hyoid bone, and the fusion of the basi-sphenoid and basi-occiput, occur at earlier stages of skeletal development and maturation.

Answer: C. Pressure wave

Explanation: A suppressor, also known as a silencer, is a device attached to the muzzle of a firearm to reduce the noise and visible signature of the gun when fired. While suppressors cannot completely silence a firearm, they are effective in reducing the pressure wave generated by the expansion of hot gases from the muzzle. The supersonic crack of the bullet, hammer noise, and flight noise are not significantly affected by a suppressor. The primary function of a suppressor is to mitigate the loud pressure wave created during the discharge of the firearm.

Answer: C. John Browning

Explanation: The Model 1900 Colt 0.38 automating was a semi-automatic pistol designed by the renowned firearms designer John Browning for Colt’s Manufacturing Company. This pistol, introduced in 1900, was one of Browning’s early successful designs and was influential in the development of subsequent semi-automatic pistols. It was a significant step forward in the evolution of self-loading pistols and marked a milestone in the history of firearms design.

Answer: A. Ammonium sulphate

Explanation: In the extraction of poisons from toxicological samples, ammonium sulfate is commonly used as a dehydrating agent. During the extraction process, ammonium sulfate helps remove water from the sample matrix, facilitating the efficient extraction of the target compounds (poisons or toxins). By dehydrating the sample, ammonium sulfate increases the solubility of the target compounds in organic solvents, allowing for better extraction and subsequent analysis.

Answer: C. Blood alcohol concentration

Explanation: The Widmark equation, developed by Swedish scientist Erik M.P. Widmark, is a widely used forensic formula to calculate the blood alcohol concentration (BAC) in an individual based on factors such as body weight, amount of alcohol consumed, and the rate of alcohol elimination from the body. This equation is particularly useful in cases related to driving under the influence (DUI) and other alcohol-related investigations, as it provides an estimate of the BAC at a specific time based on the available information.

Answer: D. TATP

Explanation: TATP, or triacetone triperoxide, is not a petroleum product. It is an organic compound that is often used as an explosive material. TATP is highly sensitive and has been involved in various terrorist attacks and improvised explosive devices (IEDs). On the other hand, bitumen, wax, and petrol (gasoline) are all petroleum products derived from the refining of crude oil.

Answer: A. Pin fire

Explanation: The pinfire, also known as the priming system, was the earliest example of a true breech-loading weapon that used a self-contained cartridge. Invented in the early 19th century, the pinfire cartridge had a small percussion cap integrated into the base of the cartridge case. When the firearm’s firing pin struck the cap, it ignited the gunpowder within the cartridge, propelling the bullet. This design marked a significant advancement in firearms technology, paving the way for more modern ammunition and firearm designs.

Answer: A. Interference with the resulting signal

Explanation: Crompton scattering, also known as non-resonant Raman scattering, is a phenomenon that occurs in Raman spectroscopy. It results in interference with the resulting Raman signal by introducing an additional broad background signal. This interference can obscure or distort the Raman peaks of interest, making it challenging to accurately interpret the spectral data. Crompton scattering is caused by the interaction of the incident laser light with the sample matrix and can be particularly problematic in samples with high fluorescence or when using certain laser wavelengths.

Answer: A. ICP – MS

Explanation: Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is a highly sensitive analytical technique used for the elemental profiling of cement. Cement is a complex material composed of various inorganic compounds, and ICP-MS is well-suited for determining the concentrations of various elements present in cement samples. The technique involves ionizing the sample using an argon plasma and then separating and detecting the resulting ions based on their mass-to-charge ratios. ICP-MS provides accurate and precise quantitative information about the elemental composition of cement, which is useful for quality control, forensic investigations, and research purposes.

Answer: D. It can distinguish the oxidation states of elements.

Explanation: Atomic emission spectroscopy (AES) is an analytical technique used to determine the elemental composition of a sample by analyzing the characteristic wavelengths of light emitted by atoms or ions in an excited state. While AES is a destructive technique (A), is commonly used for metal analysis (B), and can provide quantitative information (C), it cannot distinguish between different oxidation states of the same element. AES measures the wavelengths of emitted light, which are specific to each element but do not depend on the oxidation state of the element.

Answer: D. Attrition

Explanation: The Gustafson method is a forensic technique used to estimate the age of an individual based on the examination of dental remains. Among the parameters included in this method, attrition is the only one that can be appreciated macroscopically. Attrition refers to the gradual wearing away of the tooth surface due to mastication and other factors, which is a visible and easily observable phenomenon. The other parameters, such as root resorption, cementum apposition, and secondary dentin formation, require microscopic or radiographic examination to be evaluated.

Answer: D. (a) and (d) are correct.

Explanation: A scar is a fibrous tissue formed over a healed wound or incision, covered by epithelium (a). Scars do not contain sweat glands (b is incorrect) or hair follicles (c is incorrect), and they are generally not pigmented. The shape of scars resulting from stab wounds can often be oval or elliptical (d), reflecting the shape of the weapon used. Therefore, the correct statements regarding scars are (a) and (d).

Answer: C. Split laceration

Explanation: A split laceration is a type of wound that resembles an incised wound, which is a clean, sharp-edged cut caused by a sharp instrument like a knife or razor. Split lacerations are typically caused by blunt force trauma, where the skin is split or torn apart by the impact. The resulting wound can have clean, sharp edges similar to an incised wound, making it difficult to distinguish between the two types of wounds at times. Imprint abrasions, graze abrasions, and avulsed lacerations have distinctly different appearances from incised wounds.

Answer: C. (a), (b) and (d) are correct.

Explanation: The word “tattoo” is derived from the Polynesian word “ta tau,” meaning “to mark” (a). The process of tattooing involves impregnating a dye into the dermal layers of the skin (b). While the leaves of “lawsonia inermis” (henna) are used for temporary body art, they are not used for permanent tattooing (c is incorrect). Tattoos can be partially or completely removed through dermabrasion, a procedure that involves removing the top layers of the skin (d). Therefore, the correct statements are (a), (b), and (d).

Answer: B. (a), (b), (c) are correct.

Explanation: Ancillary investigations are additional tests or examinations that are often conducted during a medicolegal autopsy to gather more information and support the findings. These investigations include microbiology (a), which involves analyzing bacterial or viral infections; toxicology (b), which examines the presence and levels of drugs, poisons, or other substances; and radiology (c), which involves imaging techniques like X-rays or CT scans. Angiography (d), which involves visualizing blood vessels, is not routinely performed as an ancillary investigation in a standard medicolegal autopsy.

Answer: D. Henry system

Explanation: The Henry system, also known as the Henry Classification System, is the fingerprint classification system based on the analysis of all ten fingers. It was developed by Sir Edward Richard Henry, an Inspector General of Police in British India, and was first introduced in 1901. The Henry system categorizes fingerprints into primary groupings based on the ridge patterns, such as loops, whorls, and arches, and further sub-classifies them based on specific ridge characteristics. This comprehensive system revolutionized fingerprint identification and is widely used in forensic science and law enforcement agencies worldwide.

Answer: C. Gold and Zinc

Explanation: The Vacuum Metal Deposition (VMD) method is a technique used for developing latent fingerprints on non-porous surfaces. In this method, a thin layer of metal is deposited onto the surface under vacuum conditions. The metal commonly used in the VMD process is a combination of gold and zinc. The gold-zinc alloy is vaporized and deposited onto the surface, selectively adhering to the fingerprint residue. This creates a visible metallic film that reveals the fingerprint pattern, allowing for further analysis and identification.

Answer: A. Both (A) and (R) are correct.

Explanation: In the context of handwriting analysis and comparison, request standard writing refers to samples of writing obtained specifically for the purpose of comparison, typically at the request of an investigator or expert. While these requested samples can provide a sufficient amount of writing for comparison, they may not always be the ideal standard because they can be influenced by factors such as the writer’s awareness of being observed or the lack of natural writing conditions. Additionally, request standards may not necessarily reflect the contemporary writing habits of the individual at the time of the questioned document. Therefore, both the assertion (A) and the reason (R) are correct.

Answer: C. (iii) (iv) (i) (ii)

Explanation: The correct matching between the lists is as follows: (a) Amido black – (iii) Finger prints in blood (used to enhance and visualize blood fingerprints) (b) SPR – (iv) Wet surfaces (Small Particle Reagent is used to develop latent fingerprints on wet or damp surfaces) (c) Ninhydrin – (i) Paper (Ninhydrin is a reagent commonly used to develop latent fingerprints on porous surfaces like paper) (d) Gentian violet – (ii) Adhesive side of the tape (Gentian violet is a dye used to enhance and visualize latent fingerprints on adhesive surfaces like tape).

Answer: C. Writing between two lines

Explanation: Interlineation refers to the act of inserting additional writing between the lines of an existing text. This is often done to add supplementary information, corrections, or clarifications to the original text. Interlineation is distinct from writing between words (which may be considered an insertion), between letters (which may be considered an alteration), or between paragraphs (which may be considered an addition). The term “interlineation” specifically refers to the writing that occurs between the lines of an existing document.

Answer: D. Amido black

Explanation: Amido black is a reagent used in forensic science to develop latent fingerprints on porous surfaces, such as paper or cardboard. The reaction between amido black and the amino acids present in sweat residue is photosensitive, meaning it is sensitive to light. This photosensitive nature allows for the development of latent fingerprints in the dark or under low-light conditions. When amido black is applied to a surface and exposed to light, the reaction with sweat residue is inhibited, preventing the formation of visible fingerprints. Therefore, the processing and development of fingerprints using amido black must be carried out in the dark or under controlled lighting conditions.

Answer: B. Wet mortar

Explanation: A nest of sieves, which consists of a series of sieves with progressively smaller mesh sizes stacked on top of each other, is commonly used for the analysis of wet mortar samples in forensic investigations. Wet mortar, which is a mixture of cement, sand, and water, is often found at crime scenes involving construction or renovation. By passing the wet mortar sample through the nest of sieves, the various components (cement, sand particles of different sizes) can be separated and analyzed, providing valuable information for forensic purposes.

Answer: C. Binder

Explanation: In the forensic examination of paints, pyrolysis gas chromatography (Py-GC) is a valuable technique for characterizing the binder component of the paint sample. The binder is the non-volatile component of the paint that acts as a film-forming material, holding the pigments and other additives together. Py-GC involves thermally decomposing the paint sample, vaporizing the binder, and then separating and identifying the resulting compounds using gas chromatography. This technique provides information about the chemical composition and type of binder used in the paint, which can be crucial in comparing and differentiating various paint samples.

Answer: B. FBI

Explanation: The Scientific Working Group for Shoeprint and Tire Tread Evidence (SWGTREAD) was created by the Federal Bureau of Investigation (FBI) in the United States. SWGTREAD is a collaborative effort among forensic experts, law enforcement agencies, and academic institutions, focused on developing and promoting best practices, guidelines, and standards for the examination and interpretation of shoeprint and tire tread evidence. The group aims to improve the quality and consistency of forensic examinations in this area, ultimately enhancing the value of such evidence in legal proceedings.

Answer: B. Angora goat hair

Explanation: Mohair is a type of fiber obtained from the hair of the Angora goat, a breed of domestic goat known for its long, silky hair. Just as wool is obtained from the fleece of sheep, mohair is derived from the fleece of Angora goats. Mohair fibers are known for their luster, strength, and resilience, and they are commonly used in the production of high-quality textiles, such as suits, sweaters, and scarves. The other options, camel hair, Asiatic goat hair, and vicuna hair, are obtained from different animal sources.

Answer: A. Cotton

Explanation: Nodes are characteristic features found in cotton fibers. Cotton fibers are derived from the seed hairs of the cotton plant and exhibit a unique appearance under microscopic examination. Nodes are thick, irregular regions along the length of the cotton fiber, which are formed during the growth and development of the fiber. These nodes serve as distinguishing characteristics that can aid in the identification and differentiation of cotton fibers from other types of fibers in forensic fiber analysis.

Answer: B. George Greenhill

Explanation: The formula for calculating the correct rate of twist for firearms was developed by George Greenhill, a British mathematician and artillery expert. The rate of twist, also known as the rifling twist rate, refers to the number of revolutions a bullet makes per unit of barrel length as it travels down the barrel of a rifled firearm. Greenhill’s formula takes into account various factors, such as the projectile’s shape, weight, and velocity, to determine the optimal twist rate for stabilizing the bullet’s flight and ensuring accurate shooting. This formula has played a significant role in the design and manufacturing of modern rifled firearms.

Answer: A. Cartridge

Explanation: The term “Magnum Nitro Express” is associated with cartridges, specifically large-caliber rifle cartridges designed for hunting large and dangerous game. The “Nitro” in the name refers to the use of nitrocellulose-based smokeless gunpowder, which replaced the earlier black powder propellants. The “Express” term indicates that these cartridges were designed for long-range, high-velocity shooting. Magnum Nitro Express cartridges were developed in the late 19th and early 20th centuries and are known for their powerful performance and ability to effectively take down large animals like elephants, rhinos, and Cape buffalo.

Answer: A. NMR

Explanation: Nuclear Magnetic Resonance (NMR) spectroscopy is not routinely used in the forensic analysis of explosives. While NMR is a powerful analytical technique used in various fields, including chemistry and structural biology, it has limited applications in the analysis of explosives due to several reasons. Explosives are typically present in trace amounts at crime scenes, and NMR requires relatively large sample quantities. Additionally, many explosives contain paramagnetic species that can interfere with the NMR signal. Other techniques like mass spectrometry (MS), Fourier-transform infrared spectroscopy (FTIR), and thin-layer chromatography (TLC) are more commonly employed for the forensic analysis of explosives.

Answer: D. Alexander John Forsyth

Explanation: Alexander John Forsyth, a Scottish minister and chemist, revolutionized the ignition of gunpowder in the early 19th century by introducing the use of highly sensitive mercury fulminate as a primary explosive. Prior to this, gunpowder was ignited using flint and steel or other less reliable methods. Forsyth’s discovery of the explosive properties of mercury fulminate led to its adoption as a reliable and efficient primer for igniting gunpowder in firearms. This advancement played a crucial role in the development of modern percussion cap ignition systems, significantly improving the reliability and safety of firearms.

Answer: B. Acetylcholinesterase

Explanation: Organophosphorus compounds are potent inhibitors of acetylcholinesterase, an enzyme responsible for breaking down the neurotransmitter acetylcholine in the body. Acetylcholine is involved in various physiological processes, including muscle contractions, heart rate regulation, and neuronal signaling. When acetylcholinesterase is inhibited by organophosphorus compounds, acetylcholine accumulates in the synaptic clefts, leading to overstimulation of the cholinergic receptors and potentially causing severe toxicity symptoms, such as respiratory distress, seizures, and paralysis. This mechanism of action makes organophosphorus compounds highly toxic and commonly used as pesticides and chemical warfare agents.

Answer: B. Pelvis

Explanation: The Washburn index is a metric used in forensic anthropology to determine the sex of an individual based on measurements of the vertebral column. Specifically, it involves measuring the anteroposterior and transverse diameters of the first and second cervical vertebrae (atlas and axis). These measurements are then used to calculate the Washburn index, which exhibits differences between males and females due to anatomical variations in the vertebral dimensions. The Washburn index is particularly useful when other skeletal elements, such as the skull or pelvis, are fragmented or unavailable for sex determination.

Answer: D. (ii) (iv) (iii) (v)

Explanation: The correct matching between List-I and List-II is as follows: (a) Sex – (v) Steeles formula (used for sex determination based on cranial measurements) (b) Stature – (ii) Haase’s Rule (used for estimating stature from long bone measurements) (c) Race – (iv) Cephalic index (used for racial classification based on cranial measurements) (d) Age – (iii) Washburn index (used for age estimation based on vertebral measurements) The Karl Pearson formula (i) is used for various statistical analyses in forensic anthropology but is not directly associated with any of the listed parameters.

Answer: B. Pubis

Explanation: The articular surface of the pubic bone, specifically the pubic symphysis, provides reliable information for age determination in forensic anthropology. The pubic symphysis is a cartilaginous joint that connects the pubic bones in the anterior pelvis. As an individual ages, the surface of the pubic symphysis undergoes predictable morphological changes, such as the formation of ridges, furrows, and erosion. These age-related changes in the pubic symphysis can be analyzed and compared to reference standards to estimate the age of an individual at the time of death.

Answer: B. Parkman Webster case

Explanation: The Parkman-Webster case, also known as the Parkman-Harvard Murder, was a famous 19th-century murder case in Boston, Massachusetts. In this case, the victim, Dr. George Parkman, was identified from charred and dismembered remains, including jaw bones and dental structures. The identification was made possible by the unique dental work and fillings present in Parkman’s teeth, which were preserved despite the extensive burning of the remains. This case is considered a landmark in the history of forensic dentistry and the application of dental evidence in criminal investigations.

Answer: D. Cocaine Hydrochloride with baking soda

Explanation: The smokable form of cocaine, commonly known as crack cocaine, is obtained by treating cocaine hydrochloride (the salt form of cocaine) with baking soda (sodium bicarbonate). This process, known as freebasing, involves removing the hydrochloride salt from the cocaine molecule, resulting in a free base form that can be smoked. When cocaine hydrochloride is mixed with baking soda and heated, a chemical reaction occurs, producing a solid, rock-like substance that can be smoked and rapidly absorbed into the bloodstream, producing an intense and short-lived high.

Answer: A. Serum

Explanation: Antibodies are proteins produced by the immune system to recognize and neutralize foreign substances, such as pathogens or toxins. These antibodies are primarily found in the serum component of blood. Serum is the liquid portion of blood that remains after the blood has been allowed to clot and the clot (containing red blood cells, white blood cells, and other cellular components) has been removed. The serum contains various proteins, including antibodies, which are essential for the body’s immune response and are used in various diagnostic and therapeutic applications in medicine and forensic science.

Answer: A. Electrolytes, Proteins, Antibodies and Enzymes

Explanation: Saliva is a complex biological fluid produced by the salivary glands. It is primarily composed of water but also contains various other components in small quantities. These components include electrolytes (such as sodium, potassium, and chloride), proteins (like mucins, amylase, and antibodies), antibodies (immunoglobulins), and enzymes (such as amylase and lipase). The presence of these components in saliva plays crucial roles in digestion, maintaining oral health, and providing valuable forensic evidence in criminal investigations.

Answer: C. Colour

Explanation: The cortex is the central and most substantial part of the hair shaft. It derives its major forensic importance because it is embedded with pigment granules, known as melanin, which give hair its color. The distribution, concentration, and composition of these pigment granules within the cortex determine the specific color of an individual’s hair. This feature is crucial in forensic hair analysis, as it can provide valuable information for identifying individuals, establishing associations, or excluding potential suspects based on hair color comparisons.

Answer: D. Colorometric

Explanation: The Jaffe test, also known as the Jaffe reaction, is a colorometric method used for the examination of urine samples in forensic and clinical settings. It is a chemical test that involves the reaction of creatinine, a waste product present in urine, with picric acid (2,4,6-trinitrophenol). This reaction produces a distinctive orange-red color, the intensity of which is proportional to the concentration of creatinine in the urine sample. By measuring the color intensity using a colorimeter or spectrophotometer, the Jaffe test allows for the quantitative determination of creatinine levels, which can provide valuable information about kidney function and overall health.

Answer: B. GC content of sequence

Explanation: In the Polymerase Chain Reaction (PCR), the annealing temperature is primarily determined by the guanine-cytosine (GC) content of the target DNA sequence. DNA sequences with higher GC content require higher annealing temperatures, as the hydrogen bonds between G and C base pairs are stronger than those between A and T base pairs. The annealing temperature is crucial for ensuring specific binding of the primers to the target DNA sequence during the PCR cycle. It is typically calculated based on the melting temperature (Tm) of the primers, which is influenced by the GC content of the sequence. Other factors, such as primer dimer formation and magnesium concentration, can also affect the optimum annealing temperature, but the GC content is the primary determinant.

Answer: B. Intestinal epithelial cells

Explanation: The forensic DNA analysis of fecal matter (stool) is possible due to the presence of intestinal epithelial cells. These cells are shed from the lining of the intestines and are present in fecal matter. Although fecal matter primarily consists of digested food, water, and bacterial cells, it also contains sloughed-off intestinal epithelial cells that carry the individual’s DNA. By extracting and analyzing the DNA from these cells, forensic scientists can potentially identify the source of the fecal matter, which can be valuable evidence in cases involving sexual assault, identification of suspects, or linking individuals to crime scenes.

Answer: D. Narrow Wavelength bands

Explanation: In X-Ray Fluorescence Spectroscopy (XRFS), the diffracting crystal plays a crucial role in isolating and selecting specific wavelengths of X-rays for analysis. The diffracting crystal, typically made of materials like lithium fluoride or a synthetic multilayer structure, acts as a dispersive element that separates the polychromatic X-rays (containing multiple wavelengths) into narrow wavelength bands based on the principles of X-ray diffraction. By isolating these narrow wavelength bands, the diffracting crystal allows for the selective detection and analysis of characteristic X-ray emissions from different elements present in the sample, enabling their identification and quantification.

Answer: C. Californium

Explanation: In plasma desorption mass spectrometry (PDMS), the element californium (Cf) is commonly used as the source of ions for desorbing and ionizing large biomolecules like proteins and nucleic acids. Californium-252 (252Cf) is a radioactive isotope that undergoes spontaneous fission, emitting high-energy particles (fission fragments) that create a plasma when they hit a surface. This plasma is used to desorb and ionize the sample molecules, allowing for their analysis using mass spectrometry. The use of californium as the ionization source in PDMS enables the study of large, non-volatile biomolecules, making it a valuable technique in areas such as proteomics and biochemistry.

Answer: B. Bhabha Atomic Research Centre, Trombay

Explanation: The Neutron Activation Analysis (NAA) Unit for Forensic Science was established in 1971 at the Bhabha Atomic Research Centre (BARC) in Trombay, Mumbai. BARC is a premier multi-disciplinary research center in India, dedicated to the peaceful applications of nuclear energy. The NAA Unit at BARC has played a crucial role in the development and application of neutron activation analysis techniques for forensic purposes. NAA is a highly sensitive analytical technique used for elemental analysis, particularly in trace evidence examination. By irradiating samples with neutrons and analyzing the resulting gamma-ray emissions, NAA can detect and quantify various elements present in forensic samples, such as hair, gunshot residue, and trace evidence.

Answer: B. Nature of evidence

Explanation: The ideal method of collecting and packing physical evidence for transportation to a forensic science laboratory primarily depends on the nature of the evidence itself. Different types of evidence, such as biological samples, trace evidence, firearms, explosives, or documents, require specific handling, packaging, and preservation techniques to maintain their integrity and prevent contamination or degradation during transportation. The nature of the evidence dictates the appropriate collection methods, storage conditions, and packaging materials to be used. Factors like the risk of leakage, fragility, or exposure to environmental conditions are considered when determining the optimal method for collecting and packing evidence for forensic analysis.

Answer: C. Electrostatic dust print lifting device

Explanation: When a footwear print is observed on clothing or fabric, the most effective method for lifting and preserving the impression is by using an electrostatic dust print lifting device. This device works by applying an electrostatic charge to a specialized film or lifting material, which attracts and adheres to the dust particles or residue that make up the footwear impression. The electrostatic lifting technique is particularly useful for collecting footwear impressions from fabrics or other porous surfaces, as it can capture intricate details and patterns without damaging the substrate. Other methods, such as plaster casts or adhesive tapes, may be less suitable for fabric surfaces due to the risk of damage or inadequate adherence.