Theoretically, type_____________ ______ blood can be donated to all persons because it lacks_____________ ______

Correct Answer: A

Rationale: Type O lacks antigens, making it universal; AB has antigens, A and O misstate.

Correct Answer: B

Rationale: IgM is the first antibody in primary response; IgG follows.

Correct Answer: C

Rationale: Differentiation of B Cell takes place in bone marrow and functional B cells are found in Gut associated Lymphoid tissue (GALT), while T cells mature in the thymus.

Correct Answer: D

Rationale: Lysozyme splits peptidoglycan in bacterial cell walls, an enzymatic action, not complement activation.

Correct Answer: D

Rationale: New influenza variants (antigenic drift/shift) escape prior immunity, requiring updated responses.