General microbiology: laboratory safety: 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 · General microbiology: laboratory safety

Sample item

A tuberculosis laboratory needs a cabinet that protects the worker, the culture sample and the surrounding environment while processing sputum specimens. Which equipment meets this requirement?

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

The answer and the reasoning

C. Class II biological safety cabinet with HEPA-filtered laminar airflow

A Class II cabinet draws room air in through the front grille to protect the user, passes downward HEPA-filtered air over the work surface to protect the sample, and exhausts through a HEPA filter to protect the environment. A horizontal clean bench blows air toward the operator and protects only the product. Class I protects user and environment but not the sample.

Option by option

  • A. Class I biological safety cabinet

    Class I has no sterile downflow over the work area, so the sample is not protected.

  • B. Chemical fume hood

    A fume hood removes chemical vapours and does not filter microbial aerosols.

  • C. Class II biological safety cabinet with HEPA-filtered laminar airflow (correct)

    Correct. Only Class II gives three-way protection of user, sample and environment.

  • D. Horizontal laminar flow clean bench

    A horizontal clean bench blows HEPA-filtered air across the work toward the operator, protecting only the product and exposing the worker.

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 C, Class II biological safety cabinet with HEPA-filtered laminar airflow. A Class II cabinet draws room air in through the front grille to protect the user, passes downward HEPA-filtered air over the work surface to protect the sample, and exhausts through a HEPA filter to protect the environment.

Why is "Class I biological safety cabinet" not the answer?

Class I has no sterile downflow over the work area, so the sample is not protected.

Why is "Chemical fume hood" not the answer?

A fume hood removes chemical vapours and does not filter microbial aerosols.

Why is "Horizontal laminar flow clean bench" not the answer?

A horizontal clean bench blows HEPA-filtered air across the work toward the operator, protecting only the product and exposing the worker.

What concept does this question test?

It tests General microbiology: laboratory safety in Microbiology. A horizontal clean bench blows air toward the operator and protects only the product. Class I protects user and environment but not the sample.

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 General microbiology: laboratory safety?

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.