What is the consequence of granzyme entering a target cell?

Correct Answer: B

Rationale: Granzyme entering a target cell activates apoptosis pathways by inducing cell death. Firstly, granzyme activates caspases leading to cell death. Secondly, it triggers DNA fragmentation and cell shrinkage. Lastly, it enhances membrane blebbing and apoptotic body formation. The other choices are incorrect because granzyme does not neutralize toxins, inhibit cytokine secretion, or promote antigen presentation within a target cell.

Correct Answer: B

Rationale: After clonal selection and expansion, B cells differentiate into plasma cells to produce antibodies. This is crucial for the immune response as plasma cells are specialized in antibody production. B cells do not produce cytokines (choice A), initiate phagocytosis (choice C), or present antigens to T cells (choice D) post-clonal selection. Plasma cell differentiation is the key outcome of the B cell activation process, enabling the body to mount an effective immune response against pathogens.

Correct Answer: B

Rationale: The correct answer is B because adaptive immunity is characterized by antigen-specific responses and memory. This means that it can recognize and target specific antigens upon exposure and develop long-lasting immunological memory. Choice A is incorrect because physical barriers like skin are part of innate immunity, not adaptive immunity. Choice C is incorrect as adaptive immunity responds to specific antigens, not all antigens non-specifically. Choice D is incorrect because adaptive immunity typically takes longer to respond compared to innate immunity due to the need for activation and clonal expansion of specific immune cells.

Correct Answer: C

Rationale: The correct answer is C: Mucosal immunity. IgA plays a crucial role in protecting mucosal surfaces, such as the lining of the gut and respiratory tract, from pathogens. It helps prevent infections by neutralizing and blocking the entry of harmful substances. IgA is not involved in allergy mediation (choice A), placental transfer (choice B), or primary response (choice D), as those functions are typically associated with other types of antibodies. IgA's specificity for mucosal surfaces makes it uniquely suited for providing defense at these vulnerable sites.

Correct Answer: B

Rationale: The correct answer is B: Type I, II, III, and V. - Type I hypersensitivity involves IgE antibodies and immediate allergic reactions. - Type II hypersensitivity involves IgG and IgM antibodies attacking self-antigens on cells. - Type III hypersensitivity involves immune complex deposition. - Type V hypersensitivity involves autoantibodies stimulating receptors. Choices A, C, and D are incorrect because they do not include all types of hypersensitivity mediated by antibodies as specified in the question.