Which organ traps respiratory pathogens?

Correct Answer: C

Rationale: Tonsils trap respiratory pathogens; spleen filters blood, thymus matures T cells, nodes filter lymph.

Correct Answer: B

Rationale: Lymphatic fluid is rich in antibodies (produced by lymphocytes), supporting immune function, unlike iron (in blood) or specific white cells like neutrophils and basophils.

Correct Answer: B

Rationale: Secondary nodules contain active B-lymphocytes with low T-lymphocytes due to germinal centers.

Correct Answer: A

Rationale: Tonsils protect digestive and respiratory systems via antibody production.

Correct Answer: D

Rationale: Paracortex is the deep cortex with T-lymphocytes ; lymph flows from cortical to medullary sinuses (A is wrong), littoral cells are in spleen , efferent vessels exit at the hilum, not convex surface .