Which of the following sources provides the highest yield and most reliable samples for DNA fingerprinting?
What substance is measured in the vitreous humor to estimate the time since death?
In a case of hanging, the ligature marks on the neck are an example of which type of injury?
Widmark's formula helps in the measurements of blood level of:
Which of the following is NOT considered a grievous injury?
In medical negligence cases, what is the primary role of the plaintiff?
La facies sympathique is seen in ?
Gastric lavage is contraindicated in which of the following?
The odour of cyanide is similar to?
Which of the following is true about cadaveric spasm?
NEET-PG 2012 - Forensic Medicine NEET-PG Practice Questions and MCQs
Question 11: Which of the following sources provides the highest yield and most reliable samples for DNA fingerprinting?
- A. Saliva
- B. Tooth
- C. Buccal mucosa
- D. Blood (Correct Answer)
Explanation: ***Blood*** - **Blood** provides a high concentration of **nucleated cells** (e.g., white blood cells), yielding abundant and high-quality DNA. - The DNA obtained from blood is typically well-preserved and less prone to degradation or contamination compared to other sources. *Saliva* - While saliva contains DNA from **buccal epithelial cells** and white blood cells, its DNA yield can be lower and more variable due to mucous and bacterial contamination. - DNA from saliva may be more subject to degradation, especially if not collected and stored properly. *Tooth* - **Teeth** can be a good source of DNA, particularly from the **pulp**, but extraction can be challenging and destructive. - The DNA yield varies depending on the tooth's condition and the extraction method, and it is generally reserved for situations where other sources are unavailable or severely degraded. *Buccal mucosa* - **Buccal mucosa** swabs are a common and non-invasive source of DNA from **epithelial cells**. - While suitable for many applications, the DNA yield can be lower than blood, and the sample may be more susceptible to surface contamination.
Question 12: What substance is measured in the vitreous humor to estimate the time since death?
- A. Sodium
- B. Potassium (Correct Answer)
- C. Proteins
- D. Chloride
Explanation: ***Potassium*** - **Potassium** concentration in the vitreous humor increases predictably after death due to the breakdown of cellular membranes and passive diffusion from cells. - This consistent post-mortem rise makes it a reliable marker for estimating the **post-mortem interval** (PMI) or time since death. *Sodium* - While sodium is present in the vitreous humor, its post-mortem changes are not as consistent or predictable as potassium for estimating the **time since death**. - Sodium levels tend to decrease slightly after death, but this decline is influenced by various factors and is less reliable for **PMI determination**. *Proteins* - **Proteins** are generally stable in the vitreous humor for some time post-mortem, but their levels do not show a consistent or predictable change that can be used to accurately estimate the **time since death**. - Measuring protein levels is more useful in assessing specific eye pathologies rather than **PMI**. *Chloride* - **Chloride** concentrations in the vitreous humor exhibit post-mortem changes, but like sodium, they are not as precise or reliable as potassium for estimating the **post-mortem interval**. - Its diffusion out of the vitreous humor can be more variable and less consistently linear than potassium's influx.
Question 13: In a case of hanging, the ligature marks on the neck are an example of which type of injury?
- A. Laceration
- B. Bruise
- C. Contusion
- D. Printed abrasion (Correct Answer)
Explanation: ***Printed abrasion*** - Ligature marks in hanging specifically refer to a type of **abrasion** where the pattern or texture of the ligature (rope, cord, etc.) is imprinted onto the skin. - This occurs due to the **pressure and friction** of the ligature against the epidermis, causing superficial scraping and leaving a distinct pattern. *Contusion* - A **contusion**, or bruise, results from bleeding into the tissues as a consequence of blunt trauma, causing discoloration of the skin. - While some mild bruising might coexist with ligature marks, the primary and distinctive injury from a ligature is an abrasion of the skin surface, not solely bleeding underneath. *Laceration* - A **laceration** is a tear or cut in the skin and underlying tissues typically caused by the forceful impact of a blunt object or shear forces. - Ligature marks from hanging are generally superficial skin injuries and do not involve deep tearing of tissues typical of a laceration. *Bruise* - A **bruise** is another term for a contusion, involving hemorrhage into the tissues without breaking the skin. - While bleeding may occur under the ligature mark, the defining characteristic of the mark itself is the superficial scraping or impression on the skin surface, which is an abrasion, not primarily a bruise.
Question 14: Widmark's formula helps in the measurements of blood level of:
- A. Alcohol (Correct Answer)
- B. Barbiturate drugs
- C. Cocaine derivatives
- D. Benzodiazepine medications
Explanation: ***Alcohol*** - **Widmark's formula** is a widely used method to estimate an individual's **blood alcohol concentration (BAC)** based on the amount of alcohol consumed, body weight, and gender. - This formula helps in forensic toxicology and clinical settings to assess the level of **intoxication**. *Barbiturate drugs* - The levels of **barbiturate drugs** are typically measured using techniques like **gas chromatography-mass spectrometry (GC-MS)** or **high-performance liquid chromatography (HPLC)**. - While various formulas might exist for pharmacokinetic modeling of specific drugs, Widmark's formula is not applicable to barbiturates. *Cocaine derivatives* - **Cocaine and its metabolites** (e.g., benzoylecgonine) are detected and quantified in biological samples (blood, urine) using analytical methods such as **immunoassay**, **GC-MS**, or **LC-MS/MS**. - Widmark's formula is specific to alcohol metabolism and distribution, not cocaine. *Benzodiazepine medications* - The measurement of **benzodiazepine concentrations** in blood is predominantly done using **chromatographic methods** (e.g., GC-MS, LC-MS/MS) due to their complex metabolism and structural diversity. - Widmark's formula is not designed to calculate levels of benzodiazepines.
Question 15: Which of the following is NOT considered a grievous injury?
- A. Multiple facial scars
- B. Femur fracture
- C. Emasculation injury
- D. Breast contusion (Correct Answer)
Explanation: ***Breast contusion*** - A breast contusion, while painful, is generally a **minor injury** that typically resolves without long-term significant functional impairment or disfigurement. - It does not meet the criteria for a grievous injury under **IPC Section 320**, which requires severe, lasting physical harm or functional loss. *Multiple facial scars* - Multiple facial scars can lead to significant and **permanent disfigurement of the face**, which is explicitly listed as a grievous injury under IPC Section 320. - Such scarring can have profound psychological impacts and may require extensive reconstructive surgery. *Femur fracture* - A femur fracture is a **grievous injury** under IPC Section 320 as it constitutes a **"fracture or dislocation of a bone."** - Additionally, it results in **severe pain**, prolonged disability, and often requires extensive medical intervention including surgery, with potential for protracted loss of use of a limb. *Emasculation injury* - Emasculation refers to the **removal or destruction of male reproductive organs**, which is explicitly listed as a grievous injury under IPC Section 320. - This type of injury results in **permanent impairment of reproductive powers** and qualifies as privation of a member or joint.
Question 16: In medical negligence cases, what is the primary role of the plaintiff?
- A. Files case in civil court (Correct Answer)
- B. Acts as defender
- C. Gives judgement
- D. Issues summons to defendant
Explanation: ***Files case in civil court*** - The **plaintiff** is the party who initiates a lawsuit, claiming to have been harmed by the actions of another party. - In medical negligence cases, this typically involves someone who alleges injury due to substandard medical care and seeks **compensation** through the legal system. - Filing the case in civil court is the **primary and defining role** of the plaintiff. *Acts as defender* - The **defender** (or defendant) is the party against whom a lawsuit is brought, and they are responsible for responding to the plaintiff's claims. - In medical negligence, the healthcare provider accused of negligence would be the defender. *Gives judgement* - Giving judgment is the function of the **court** or judge and is a neutral adjudication of the facts and application of the law. - The plaintiff's role is to present their case and evidence to persuade the court, not to issue the final decision. *Issues summons to defendant* - Issuing summons is a **court function**, not the plaintiff's role. - The court issues summons after the plaintiff files the case, directing the defendant to appear and respond to the allegations.
Question 17: La facies sympathique is seen in ?
- A. Hanging (Correct Answer)
- B. Strangulation
- C. Myocardial insufficiency
- D. Railway accident
Explanation: ***Hanging*** - **La facies sympathique** is a term used to describe the facial appearance in cases of **hanging**, characterized by a serene or peaceful look often associated with venous congestion rather than extreme distress. - This appearance is due to the obstruction of venous return from the head while arterial supply continues for a short period, leading to a relatively natural facial expression. *Strangulation* - **Strangulation** typically results in a more dramatic and distressed facial appearance, often with prominent signs of struggle, petechial hemorrhages, and cyanosis. - The compression of both arteries and veins, along with the trachea, leads to rapid and severe cerebral anoxia and overt signs of asphyxia. *Myocardial insufficiency* - **Myocardial insufficiency** (heart failure) usually presents with signs of impaired circulation, such as pallor, cyanosis (especially acrocyanosis), edema, and shortness of breath, but not a specific "sympathetic facies." - The facial expression would more likely reflect distress from dyspnea or discomfort rather than a serene appearance. *Railway accident* - Fatalities from **railway accidents** typically involve severe trauma, disfigurement, and extensive injuries to the head and body. - The facial appearance in such cases would be consistent with massive blunt force trauma, lacerations, or crush injuries, which are inconsistent with "la facies sympathique."
Question 18: Gastric lavage is contraindicated in which of the following?
- A. Organophosphorus Poisoning
- B. Dhatura poisoning
- C. Arsenic poisoning
- D. Kerosene poisoning (Correct Answer)
Explanation: ***Kerosene poisoning*** - Gastric lavage is contraindicated in **kerosene poisoning** due to the high risk of **aspiration pneumonitis**. - Kerosene is a **hydrocarbon**, and aspiration of even small amounts can cause severe lung damage. *Arsenic poisoning* - **Gastric lavage** can be performed in arsenic poisoning, especially if the ingestion occurred recently, to remove unabsorbed toxin. - Activated charcoal is less effective for arsenic, making lavage a more relevant intervention in acute settings. *Organophosphorus Poisoning* - Gastric lavage is generally recommended within an hour of ingestion for **organophosphorus poisoning** to remove the toxic substance. - This helps reduce systemic absorption and mitigate the severe **cholinergic crisis** caused by these agents. *Dhatura poisoning* - **Gastric lavage** is indicated in dhatura poisoning, particularly if presenting within a few hours of ingestion, to remove unabsorbed **atropine-like alkaloids**. - This helps in reducing the **anticholinergic effects** and improving patient outcomes.
Question 19: The odour of cyanide is similar to?
- A. Rotten egg
- B. Fish
- C. Fruity
- D. Bitter almond (Correct Answer)
Explanation: ***Bitter almond*** - The classic description of **cyanide odor** is that of **bitter almonds**. This specific scent is a key indicator during forensic investigations or in cases of suspected poisoning. - However, not everyone can detect this smell due to a **genetic trait** that affects the ability to perceive it. *Rotten egg* - A **rotten egg** odor is characteristic of **hydrogen sulfide (H2S)**, a highly toxic gas. - This gas is often produced by the decomposition of organic matter and does not indicate cyanide exposure. *Fish* - A **fishy odor** is typically associated with compounds like **amines**, such as **trimethylamine**, which are found in decomposing fish or certain medical conditions like **trimethylaminuria**. - This smell is distinct from the bitter almond scent of cyanide. *Fruity* - A **fruity odor** can be associated with various substances, including **ketones** in conditions like **diabetic ketoacidosis** or certain **volatile organic compounds**. - This scent is not characteristic of cyanide poisoning.
Question 20: Which of the following is true about cadaveric spasm?
- A. Occurs 2-3 h after death
- B. Some particular group of muscles are involved (Correct Answer)
- C. Involves involuntary muscles
- D. Disappears with rigor mortis
Explanation: ***Some particular group of muscles are involved*** - **Cadaveric spasm** is characteristically a **localized or partial phenomenon**, typically affecting specific muscle groups that were in intense contraction at the moment of death. - Classic examples include **hand gripping a weapon** (homicide/suicide), **clutching grass or mud** (drowning), or **specific limb muscles** during extreme physical exertion. - While generalized cadaveric spasm can theoretically occur, it is **usually partial and localized** to the muscles involved in the terminal activity. - This is a key distinguishing feature used in **medico-legal investigations** to determine circumstances of death. *Occurs 2-3 h after death* - This describes the typical onset of **rigor mortis**, which begins 2-3 hours post-mortem and follows a predictable progression. - **Cadaveric spasm** occurs **instantaneously at the moment of death** with **no flaccid interval**, unlike rigor mortis which has a pre-rigor flaccid phase. *Disappears with rigor mortis* - This is **incorrect**. Cadaveric spasm does **not disappear** when rigor mortis develops. - Instead, cadaveric spasm **persists and merges into rigor mortis**, becoming indistinguishable from it once rigor mortis is fully established. - Both cadaveric spasm and rigor mortis eventually resolve together during the **resolution phase** (24-36 hours post-mortem), not separately. *Involves involuntary muscles* - **Cadaveric spasm** affects only **voluntary (skeletal) muscles** under conscious control. - Involuntary muscles such as cardiac muscle and smooth muscles of internal organs are **not involved** in cadaveric spasm.