Toxicology: abrus precatorius: practice question

A Forensic Medicine question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Forensic Medicine · Toxicology: abrus precatorius

Sample item

A child chews the red and black seeds of Abrus precatorius (jequirity). The toxin abrin acts by which mechanism?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Inhibition of protein synthesis by damaging the 60S ribosomal subunit

Abrin is a toxalbumin that removes an adenine from ribosomal RNA, inactivating the 60S subunit and stopping protein synthesis. Ricin from castor seeds acts in the same way. Chewed seeds cause severe gastroenteritis, dehydration and multi-organ injury, whereas intact seeds often pass without harm.

Option by option

  • A. Inhibition of protein synthesis by damaging the 60S ribosomal subunit (correct)

    Correct. Abrin is a ribosome-inactivating protein.

  • B. Inhibition of acetylcholinesterase

    Acetylcholinesterase inhibition is the action of organophosphates and carbamates.

  • C. Uncoupling of oxidative phosphorylation

    Uncoupling of oxidative phosphorylation is the action of agents such as dinitrophenol.

  • D. Blockade of sodium channels

    Sodium channel blockade describes local anaesthetics and some other toxins, not abrin.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Forensic Medicine question

What is the answer to this Forensic Medicine question?

The best answer is A, Inhibition of protein synthesis by damaging the 60S ribosomal subunit. Abrin is a toxalbumin that removes an adenine from ribosomal RNA, inactivating the 60S subunit and stopping protein synthesis.

Why is "Inhibition of acetylcholinesterase" not the answer?

Acetylcholinesterase inhibition is the action of organophosphates and carbamates.

Why is "Uncoupling of oxidative phosphorylation" not the answer?

Uncoupling of oxidative phosphorylation is the action of agents such as dinitrophenol.

Why is "Blockade of sodium channels" not the answer?

Sodium channel blockade describes local anaesthetics and some other toxins, not abrin.

What concept does this question test?

It tests Toxicology: abrus precatorius in Forensic Medicine. Ricin from castor seeds acts in the same way. Chewed seeds cause severe gastroenteritis, dehydration and multi-organ injury, whereas intact seeds often pass without harm.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Toxicology: abrus precatorius?

Learn postmortem changes with their timelines, and toxicology as poison, sign, test and antidote. Then use the flashcards and the other Forensic Medicine questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.