Blood and immunity: antigen presentation: practice question

A Physiology 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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Physiology · Blood and immunity: antigen presentation

Sample item

On a lymph node section, a cell expresses MHC class II constitutively, takes up antigen in tissues, migrates to the node and is the most effective cell for priming naive T cells. Which cell is this?

AMast cellBDendritic cellCNatural killer cellDPlasma cell

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

The answer and the reasoning

B. Dendritic cell

Dendritic cells are the professional antigen presenting cells that prime naive T cells because they express high MHC class II and costimulatory molecules and migrate to lymph nodes. Natural killer cells and mast cells do not present antigen to naive T cells. Plasma cells secrete antibody and have lost most surface MHC II.

Option by option

A. Mast cell
Mast cells release histamine in allergy and are not primary presenters to naive T cells.
B. Dendritic cell (correct)
Correct. Dendritic cells are the key antigen presenting cells for naive T cells.
C. Natural killer cell
Natural killer cells kill infected or tumour cells using missing-self recognition and do not prime naive T cells.
D. Plasma cell
Plasma cells are terminally differentiated antibody secretors with little surface MHC class II.

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.

Questions about this Physiology question

What is the answer to this Physiology question?

The best answer is B, Dendritic cell. Dendritic cells are the professional antigen presenting cells that prime naive T cells because they express high MHC class II and costimulatory molecules and migrate to lymph nodes.

Why is "Mast cell" not the answer?

Mast cells release histamine in allergy and are not primary presenters to naive T cells.

Why is "Natural killer cell" not the answer?

Natural killer cells kill infected or tumour cells using missing-self recognition and do not prime naive T cells.

Why is "Plasma cell" not the answer?

Plasma cells are terminally differentiated antibody secretors with little surface MHC class II.

What concept does this question test?

It tests Blood and immunity: antigen presentation in Physiology. Natural killer cells and mast cells do not present antigen to naive T cells. Plasma cells secrete antibody and have lost most surface MHC II.

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 Blood and immunity: antigen presentation?

For each system, sketch the key graph (pressure–volume loop, oxygen dissociation curve, nephron handling) and explain it aloud. Then use the flashcards and the other Physiology 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.