Fusion between a plasma cell and a tumour cell creates a

Correct Answer: D

Rationale: Hybridomas are formed by fusing plasma cells with tumor cells to produce monoclonal antibodies, unlike myelomas or lymphoblasts.

Correct Answer: C

Rationale: Most AIDS deaths are from opportunistic infections like pneumonia ; not highly infectious or low fatality .

Correct Answer: B

Rationale: Echinoderms lack adaptive immunity (T/B cells); bony fish have it.

Correct Answer: C

Rationale: Protein C inhibits inflammation; TNF-α promotes it.

Correct Answer: C

Rationale: The lymphatic system returns fluid and proteins and transports lipids, but not hormones to intestinal muscle.