Alcohol and Illicit liquid is the first topic in our Forensic Toxicology MCQs series for the preparation of NTA UGC NET /JRF, FACT and FACT+, University PG Entrance Exam (DU, GFSU, etc. ), or other entrance examinations across the globe.
Attention Users: For systematic learning, please refer to the index page of the Forensic Toxicology MCQs Page. Here, we listed all the MCQs based on the NTA UGC syllabus.
Alcohol and Other Illicit Liquids MCQs in Forensic Toxicology
1. Which of the following is a hepatotoxic poison:
- Alcohol
- Atropine
- Morphine
- Amphetamine
Answer and Explanation
Answer: (1) Alcohol
Explanation: Hepatotoxic poisons are those substances that primarily affect the liver by directly damaging the liver tissues or blocking a metabolic process.
2. Blindness can be caused by the following:
- Ethanol
- Methanol
- Glycol
- Propanol
Answer and Explanation
Answer: (2) Methanol
Explanation: Methanol has highly toxic effects when it gets metabolized to formic acid in humans. Moreover, even 10ml of pure methanol can cause permanent optical damage that leads to blindness.
3. Ethanol is absorbed into the blood from:
- Stomach and small intestine
- Liver and large intestine
- Kidney and liver
- Stomach and large intestine
Answer and Explanation
Answer: (1) Stomach and small intestine
4. Alcohol is oxidized to acetaldehyde in the liver by:
- Peroxidase
- Glyoxylate
- Phospho glucoamylase
- Alcohol dehydrogenase
Answer and Explanation
Answer: (4) Alcohol dehydrogenase
Explanation: Alcohol dehydrogenase (ADH) enzymes metabolize the alcohol into acetaldehyde (a carcinogen) which further transforms into acetate by the action of aldehyde dehydrogenase (ALDH) and finally into carbon dioxide and water.
5. Malting, mashing, brewing, fermentation, maturing, finishing are the steps involved in the production of
- Wine
- Beer
- Gin
- Whisky
Answer and Explanation
Answer: (2) Beer
Explanation:-> Wine productions: crushing and pressing fermentation, clarification, and then aging and bottling.
-> Gin production is a two-stage process, first, a base ‘neutral spirit’ is made, and second is, re-distillation by the addition of flavored seeds, berries, roots, fruits and herbs, and spices.
-> Whisky production involves steps such as malting, mashing, fermentation, and distillation.
6. ‘Proof’ in alcoholic drinks is
- equals to the percentage of alcohol contents
- 12/13 parts of alcohol percentage
- twice of the percentage of alcohol contents
- 8% of the alcoholic percentage
Answer and Explanation
Answer: (3) Twice the percentage of alcohol contents
Explanation: -> In general, ‘Proof’ or ‘proof spirit’ is defined as twice the alcohol (ethanol) content by volume.
-> Eg: 50% ethanol is 100 proof.
-> Spirits weaker than 57.06% are called underproof, else called overproof.
7. Legal limit of blood alcohol levels for driving in India as prescribed by the Motor vehicle act,1988 is
- 50 mg per 100 ml of blood
- 60 mg per 100 ml of blood
- 30 mg per 100 ml of blood
- 80 mg per 100 ml of blood
Answer and Explanation
Answer: (3) 30 mg per 100 ml of blood
Explanation: As per Section 185 of the Motor Vehicles Act, 1988; the alcohol legitimate limit is 30 mg per 100 ml.
8. Assertion (A): Ethyl alcohol forms metabolite formaldehyde in the body.
Reason (R): Formaldehyde is the metabolic end product of ethyl alcohol in the body.
- Both (A) and (R) are false
- Both (A) and (R) are true but (R) is not the correct explanation of (A)
- (A) is false but (R) is true
- Both (A) and (R) are true
Answer and Explanation
Answer: (1) Both (A) and (R) are false
Correct Explanation:
-> Correct Assertion (A): Ethanol is primarily metabolized to acetaldehyde and then to acetic acid in the liver.
-> Correct Reason (R): The primary metabolic end products are acetaldehyde and acetic acid (acetate).
More Explanation: More than 90% of ingested ethanol is metabolized in the body to acetaldehyde and acetate.
-> Step1: Ethanol is metabolized in the liver to acetaldehyde via three distinct enzymatic pathways: (1) alcohol dehydrogenase (ADH), (2) microsomal ethanol oxidizing system, (MEOS), and (3) catalase & P450 2E1 (CYP2E1).
-> Step 2: Aldehyde gets converted into acetate by the action of aldehyde dehydrogenase (ALDH).
-> Final Conversion: Acetic acid can be further metabolized into carbon dioxide and water, or it can enter the citric acid cycle for energy production.
-> In Case of Chronic Drinking: Ethanol forms formaldehyde metabolite by the action of an enzyme called Cytochrome P450 2E1 (CYP2E1).
-> This enzyme plays a role in the metabolism of ethanol to acetaldehyde, especially when the primary pathway (ADH) is saturated.
-> Moreover, CYP2E1 is only active when a person consumes too much alcohol, and a small amount of alcohol can be removed by the interaction with fatty acid to form fatty acid ethyl esters (FAEEs).
Reference: Alcohol Metabolism: An Update by NIH
9. Assertion (A): Alcohol gives energy but it is not considered food.
Reason (R): Alcohol does not have protein, vitamins, or nutrients.
Codes :
- Both (A) and (R) are correct
- Both (A) and (R) are incorrect
- (A) is correct, and (R) is incorrect
- (A) is incorrect and (R) is correct
Answer and Explanation
Answer: (1) Both (A) and (R) are correct
10. Quantitative estimation of ethyl alcohol can be done properly in:
(i) Urine (ii) Saliva (iii) Blood (iv) Perspiration
- (i) and (ii)
- (ii) and (iii)
- (i) and (iii)
- (iii) and (iv)
Answer and Explanation
Answer: (3) Both urine and blood
Explanation: To quantify the ethyl alcohol value, urine or blood sample can be used.
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 antidote reduce the action of the alcohol dehydrogenase enzyme (ADH) by the means of competitive inhibition.
Reference: METHANOL: Systemic Agent
12. Assertion (A): Methanol consumption causes blindness.
Reason (R): Because of the metabolic products like lactic acid and acetone
- (A) is false but (R) is true
- Both (A) and (R) are false
- (A) is true but (R) is false
- Both (A) and (R) are true
Answer and Explanation
Answer: (3) (A) is true but (R) is false
Correct Reason: Methanol has highly toxic effects when it gets metabolized to formic acid in humans (not into lactic acid).
13. Ethanol is produced by the fermentation of sugar by:
- Yeast
- Glycerin
- Alkaloid
- Both (1) and (2)
Answer and Explanation
Answer: (1) Yeast
Explanation: Ethanol is produced by microbial fermentation of sugar by yeast.
14. Assertion(A): Methanol is poisonous to human beings.
Reason(R): Because of metabolism methyl alcohol forms formaldehyde as the final product.
- Both (A ) and (R) are true
- Both (A) and (R) are true But (R) is not the correct explanation of (A)
- (A) is true but (R) is False
- (A) is False But (R) is false
Answer and Explanation
Answer: (3) (A) is true but (R) is False
Correct Reason: Methanol is metabolized to folic acid, folinic acid, carbon dioxide, and water as the end product.
15. Assertion (A): Methanol is a CNS depressant and toxicity is mainly due to formic acid.
Reason (R): Because Methanol is metabolized by the liver.
- Both (A) and (R) are true.
- Both (A) and (R) are false.
- (A) is true and (R) is false.
- (A) is false and (R) is true.
Answer and Explanation
Answer: (1) Both (A) and (R) are true.
Explanation: Methanol is metabolized by the liver to an end product of folic acid, folinic acid, carbon dioxide, and water.
Methanol-> Formaldehyde (via alcohol dehydrogenase; liver)-> Formic acid (via aldehyde dehydrogenase)-> Folic acid, folinic acid, carbon dioxide, and water.
16. The enzyme present in the liver which metabolizes alcohol is called as
- Alcohol peroxidase
- Alcohol dehydrogenase
- Alcohol phosphatase
- Alcohol esterase
Answer and Explanation
Answer: (2) Alcohol dehydrogenase
Explanation: Alcohol dehydrogenase (ADH) enzymes metabolize the alcohol into acetaldehyde (a carcinogen) which further transforms into acetate by the action of aldehyde dehydrogenase (ALDH) and finally into carbon dioxide and water.
17. ‘Biphasic Effect’ is associated with which of the following
- Alcohol Drinking
- Cocaine abuse
- Charas Smoking
- LSD abuse
Answer and Explanation
Answer: (1) Alcohol Drinking
Explanation: Biphasic effects refers to stimulant effects of alcohol prior to (precede) sedative alcohol effects during a drinking episode.
-> Stimulant effects include increased motor activity, talkativeness, and euphoria (happiness and positive mood) at lower doses and during rising BACs.
Source: Forensic Issues in Alcohol Testing by Steven B. Karch
Note: Jump to Main Page of Forensic MCQs in Toxicology
In question no. 8 it’s methyl alcohol not ethyl alcohol which gets converted into formaldehyde
Yes. Correct. Updated.