Sterilisation: practice question

A Microbiology 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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Microbiology · Sterilisation

Sample item

Which item is best sterilised in a hot air oven rather than an autoclave?

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

The answer and the reasoning

A. Anhydrous oils and powders

Dry heat penetrates oils, greases and powders that moist heat cannot reach, and it suits glassware and metal instruments. Rubber, liquids such as media and linen are better handled by steam sterilisation.

Option by option

  • A. Anhydrous oils and powders (correct)

    Steam cannot penetrate oils or dry powders, so dry heat is needed.

  • B. Culture media

    Culture media contain water and are sterilised by steam.

  • C. Rubber gloves

    Rubber gloves would deteriorate at dry heat temperatures.

  • D. Surgical dressings

    Cloth dressings can scorch in dry heat and are autoclaved.

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.

More Microbiology questions

Questions about this Microbiology question

What is the answer to this Microbiology question?

The best answer is A, Anhydrous oils and powders. Dry heat penetrates oils, greases and powders that moist heat cannot reach, and it suits glassware and metal instruments.

Why is "Culture media" not the answer?

Culture media contain water and are sterilised by steam.

Why is "Rubber gloves" not the answer?

Rubber gloves would deteriorate at dry heat temperatures.

Why is "Surgical dressings" not the answer?

Cloth dressings can scorch in dry heat and are autoclaved.

What concept does this question test?

It tests Sterilisation in Microbiology. Rubber, liquids such as media and linen are better handled by steam sterilisation.

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 Sterilisation?

Make a one-line identity card for each organism: shape and stain, defining test, toxin, disease and drug. Then use the flashcards and the other Microbiology 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.