Which of the following types of antigen presenting cells (APCs) is critical in uptake and presentation of antigen to T cells?

Correct Answer: D

Rationale: All three (macrophages, dendritic cells, B cells) are APCs critical for antigen uptake and presentation to T cells; since E is moved to D, D is correct for all.

Correct Answer: D

Rationale: Penicillin is a small hapten that requires conjugation to a carrier protein to elicit an immune response.

Correct Answer: D

Rationale: The Fc region interacts with receptors on immune cells and complement proteins.

Correct Answer: C

Rationale: Papain cleaves above the hinge region, yielding two Fab fragments and one Fc.

Correct Answer: D

Rationale: Western blotting separates proteins by size and uses antibodies to characterize antigens biochemically in complex mixtures.