What stage of an adaptive immune response involves secretion of antibody from a large plasma cell with extensive endoplasmic reticulum?

Correct Answer: C

Rationale: The effector phase includes antibody secretion by plasma cells, which have extensive ER for protein production.

Correct Answer: D

Rationale: Effective immunogens (e.g., proteins) don't require carriers; this is true for haptens, not standalone immunogens.

Correct Answer: C

Rationale: The Fab region binds antigens via its variable domains, formed by light and heavy chains.

Correct Answer: C

Rationale: Pepsin cleaves below the hinge region, producing F(ab')2 fragments.

Correct Answer: A

Rationale: ELISA uses an enzyme-linked antibody to detect antigens with high sensitivity and simplicity, making it ideal for this purpose.