The exon encoding the V region of an immunoglobulin protein is generated by a process of somatic recombination. This recombination event brings V gene and J gene segments together:

Correct Answer: B

Rationale: V-J recombination maximizes CDR3 diversity ; not all cells , not splicing , or precise .

Correct Answer: D

Rationale: Antibodies are proteins made of polypeptide chains, specific to adaptive immunity, not amino acids, lipids, or carbohydrates.

Correct Answer: D

Rationale: Cytotoxic T cells destroy infected cells via perforin and granzymes, unlike macrophages (phagocytosis), plasma cells (antibodies), or B cells (humoral).

Correct Answer: B

Rationale: Eosinophils target antibody-coated parasites (e.g., helminths) via degranulation, unlike macrophages, neutrophils, or basophils.

Correct Answer: D

Rationale: The BCR includes Igα and Igβ signaling proteins with the antibody (e.g., IgG), making all components correct.