Attention Users: For systematic learning, please prefer to check the index page of the Forensic Toxicology MCQs Page. Here, we listed all the MCQs based on the NTA UGC syllabus.
1. In the case of the poisoning of a living person the following physical evidence is collected and preserved:
(i) Vomit (ii) Excreta (iii) Viscera (iv) Blood
- (i), (ii), and (iv) are correct
- (i), (ii), and (iii) are correct
- (ii), (iii), and (iv) are correct
- (i), (ii), (iii), and (iv) are correct
Answer and Explanation
Answer: (1) (i), (ii), and (iv) are correct
Explanation: Viscera can’t be taken from a living man because other fluids such as vomit and blood (or excreta) are enough for poison detection. However, it can only be taken when the person is dead because, with it, un-digestive food and manner of death can be determined.
2. During absorption of the drug in the human body through passive diffusion, the rate of diffusion is determined by
- Fick’s law
- Henry’s law
- Beer’s law
- Schanker’s law
Answer and Explanation
Answer: (1) Fick’s law
Explanation: Fick’s Law states that the rate of diffusion is directly proportional to both the surface area and concentration difference and inversely proportional to the thickness of the membrane.
3. In the analysis of poisons, the sequence of events in chronological order is:
- Extraction, group tests, tissue homogenization, and specific tests
- Tissue homogenization, extraction, group tests, and specific tests
- Group tests, tissue homogenization, extraction, and specific tests
- Extraction, tissue homogenization, group tests, and specific tests
Answer and Explanation
Answer: (2) Tissue homogenization, extraction, group tests, and specific tests
Explanation:
-> Tissue homogenization— is a process of lysing the cell so that intracellular content like protein, DNA, RNA, small molecules, can be released.
-> Extraction — Fluids are extracted for the group analysis
-> Group tests— These tests are done to find the type of components in the blood.
-> Specific tests — To determine the specific data from a group test. For example, blood in alcohol is a group test and determining whether it is ethyl alcohol or methyl alcohol is the specific test.
4. Apart from tobacco-based products, a nasal swab is also collected for
- Morphine
- Caffeine
- Cannabis
- Cocaine
Answer and Explanation
Answer: (4) Cocaine
Explanation: Cocaine is usually taken as nose sniffs leaving a high concentration of it in nasal liquid.
5. Assertion (A): The impurity profile of an illicit drug is performed by analyzing natural components, by product, cutting agents which help to generate a complete history of the sample and does in its characterization.
Reason(R): It is used to establish specific links between two or more illicit samples.
- Both (A) and (R) are true and (R) is the correct explanation of (A).
- Both (A) and (R) are true and (R) is not the correct explanation of (A)
- (A) is true but (R) is false
- (A) is false but (R) is true
Answer and Explanation
Answer: (1) Both (A) and (R) are true and (R) is the correct explanation of (A).
Read More (book): Drug Characterization/Impurity Profiling: Manual for use by national law enforcement authorities and Drug testing laboratories
6. Considering mode of administration, poison acts more rapidly when:
- Inhaled in a gaseous state
- Injected intramuscularly
- Injected subcutaneously
- Applied to skin
Answer and Explanation
Answer: (1) Inhaled in a gaseous state
Explanation: While talking about the physical state of poison, gases and vapors act more quickly than fluid poisons because they are absorbed immediately.
7. Which of the following is used as a dehydrating agent during the extraction of poisons from toxicological samples?
- Ammonium sulphate
- Ferrous Chloride
- Sodium Tungstate
- Ammonium Nitrate
Answer and Explanation
Answer: (1) Ammonium sulphate
8. Assertion (A): Free sulphuric acid is rarely found in stomach contents in acid poisoning cases.
Reason (R): Because either it is vomited out or neutralized by alkalies given as antidotes.
Codes:
- Both (A) and (R) are incorrect
- (A) is correct, but (R) is incorrect
- Both (A) and (R) are correct
- (A) is incorrect, but (R) is correct
Answer and Explanation
Answer: (3) Both (A) and (R) are correct.
9. Ammonium sulphate method is used for the extraction of the following poison from Viscera:
- Volatile
- Metallic
- Insecticides
- Non-volatile Organic poisons
Answer and Explanation
Answer: (4) Non-volatile Organic poisons
Explanation: For extraction of non-volatile organic poison, common extraction methods are solvent extraction, Stas-Otto, Digestion with ammonium sulphate. Some modern methods of non-volatile organic poisons are paired ion extraction chromatography, HPTLC, and solid-phase extraction.
-> In solvent extraction, the 50gm of viscera are mixed with 5 gm of ammonium sulphate and 100 ml of diethyl ether. The mixture is then mixed and kept overnight.
References: Isolation and Extraction of Poison
10. The following poisons are extracted from the alcoholic extract of Viscera:
(i) Croton (ii) Oxalate (iii) Copper (iv) Curare
Codes:
- (i) and (ii) are true
- (iii) and (ii) are true
- (ii) and (iv) are true
- (i) and (iv) are true
Answer and Explanation
Answer: (4) (i) and (iv) are true
Explanation:
-> Curare: This is a plant-derived toxin used historically in hunting (used on arrow tips) and warfare, known for its muscle-paralyzing effects. Active principle is Tubocurarine.
-> Croton oil, derived from the seeds of the Croton tiglium plant. Active principles are crotin (toxalbumin) and crotonoside (glycoside).
11. Ethanol is used as an antidote in methanol poisoning because:
- Ethanol competes for choline esterase enzyme
- Ethanol by-product is formic acid
- Ethanol competes for ADH enzyme
- Ethanol is cheap and easily available
Answer and Explanation
Answer: (3) Ethanol competes for ADH enzyme
Explanation: Two common antidotes for the treatment of methanol poisoning: Fomepizole and ethanol.
-> Both antidotes reduce the action of the alcohol dehydrogenase enzyme (ADH) by the means of competitive inhibition.
Reference: METHANOL: Systemic Agent
12. Which of the following are the advantages of solid-phase extraction over liquid extraction?
A. Small Sample Size
B. High Solvent Consumption
C. Emulsion Formation
D. High Extraction Efficiency
Choose the correct answer from the options given below:
- B and C only
- A and B only
- A and D only
- C and D only
Answer and Explanation
Answer: (3) A and D only
Explanation: Advantages of Solid Phase Extraction (SPE) over Liquid-Liquid Extraction (LLE) are:
-> Low solvent consumption
-> Provision of cleaner extracts
-> Ease of automation
-> High extraction efficiency for certain drugs
-> Small sample volume
13. Ammonium Sulphate method is used for the detection of:
- Volatile poisons
- Insecticides
- Alkaloids
- Metallic poisons
Answer and Explanation
Answer: (3) Alkaloids
Explanation: Ammonium sulphate method is the most common method for the extraction and detection of non-volatile poisons and alkaloids. In this method, 50gm of viscera is mixed with 5 gm of ammonium sulphate and 100 ml of diethyl ether. And the mixture is then mixed and kept overnight.
14. Which of the following is the most appropriate sample to be preserved during an autopsy in case of poisoning by digitalis purpura?
- Spleen
- Uterus
- Spinal Cord
- Heart
Answer and Explanation
Answer: (4) Heart
Explanation: Following are some samples preserved in poisoning:
-> Heart: Strychnine, digitalis
-> Spinal cord: Strychnine
-> CSF: Alcohol
-> Vitreous humor: Alcohol, chloroform
-> Uterus: Criminal abortion
15. Which of the following are the antidotes in case of methanol poisoning?
A. Acetylcysteine
B. Ethanol
C. Hydroxy Cobalamine
D. 4-Methyl Pyrazole
Choose the most appropriate answer from the options given below:
- A and B only
- B and D only
- C and D only
- A and C only
Answer and Explanation
Answer: (2) B and D only
Explanation:
-> Ethanol and 4-methyl pyrazole (fomepizole) is competitive inhibitor of alcohol dehydrogenase and inhibits the formation of aldehyde and formic acid.
16. Pralidoxime is used in the treatment of this poison:
- Aluminum Phosphide
- Endrin
- Parathion
- Pyrethrins
Answer and Explanation
Answer: (3) Parathion
Explanation: Pralidoxime is used for the treatment of organophosphate poisoning. And some of the common organophosphate poisons are malathion, parathion (Folidol), diazinon, fenthion, dichlorvos, soman, and sarin.
17. Which of the following is the major metabolite of methyl alcohol on oral administration?
- Propionic Acid
- Acetic Acid
- Formic Acid
- Valeric Acid
Answer and Explanation
Answer: (3) Formic Acid
Explanation:
-> Stage 1: Methyl alcohol is metabolized in the liver via alcohol dehydrogenase into formaldehyde.
-> Stage 2: Formaldehyde is subsequently metabolized via aldehyde dehydrogenase into formic acid (major).
-> Stage 3: Formic acid lastly metabolized to folic acid, folinic acid, carbon dioxide, and water.
18. The antidote used in the treatment of Endrin is:
- Atropine
- Pralidoxime
- BAL
- None of the above
Answer and Explanation
Answer: (4) None of the above
Explanation: Endrin is an organochloride compound, and there is no specific antidote available for organochlorine poisons.
19. Dry Ash method is used for the extraction of the following poisons from viscera:
- Metallic poison
- Volatile poison
- Non-Volatile poison
- Vegetable poison
Answer and Explanation
Answer: (1) Metallic poison
Explanation: Dry Ashing is a metallic poison extraction technique that destroys all organic compounds by the application of an ashing temperature of 450 to 550 °C. Moreover, magnesium nitrate is commonly used as an ashing aid.
20. ‘Stass-Otto’ process is used for:
- Extraction of poisons
- Extraction of DNA
- Extraction of antigens
- Isolation of compliments
Answer and Explanation
Answer: (1) Extraction of poisons
Explanation: In Stas’s otto process, the extraction of alkaloids by digesting the sample with alcohol and tartaric acid and then extracting it with ether or chloroform.
21. Which of the following pH will be selected for good extraction of morphine from urine by using a direct solvent extraction method
- pH 2
- pH 4
- pH 6
- pH 9
Answer and Explanation
Answer: (4) pH 9
Explanation: Various pH values along with buffer for drugs for extraction using direct solvent extraction methods:
-> Barbiturates: eluted at acid pH 2.2 using a citrate buffer
-> Stimulants: eluted at basic pH 11 with a carbonate buffer.
-> Narcotic analgesics and Phenothiazines: eluted at basic pH of 9.3 using a borate buffer.
-> Amphetamines: eluted at pH 9.3 and approx 1/3 of eluant with pH11.
-> Morphine is an opiate (narcotic) analgesic. So, the pH would be pH9.3 with borate buffer.
Source: Drug Addiction I: Morphine, Sedative/Hypnotic, and Alcohol
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