blood sinusoid of red pulp collect blood in

Correct Answer: C

Rationale: Blood sinusoids collect blood into venous sinuses in red pulp.

Correct Answer: A

Rationale: Mononuclear phagocytes (macrophages) have irregular surfaces with pseudopodia for phagocytosis ; Golgi and sER are present but not defining , peroxisomes are not notable , nuclei vary .

Correct Answer: C

Rationale: C3 is the most abundant complement protein , central to all activation pathways; C1, C2, C4 are less abundant.

Correct Answer: A

Rationale: TCRs are alpha-beta or gamma-delta; AB/CD/YD/CD are not standard notations.

Correct Answer: B

Rationale: Central tolerance ensures T cells recognize self-MHC without attacking self ; not just foreign , not attack self , not B cells .