In LN naïve T cells and activated dendritic cells interact in the

Correct Answer: C

Rationale: The correct answer is C: Paracortex. Naïve T cells circulate through the blood and lymphatic system until they encounter antigens presented by activated dendritic cells in the paracortex of lymph nodes. The paracortex is the region where T cell activation and proliferation occur, leading to an immune response. The subcapsular sinus (A) is primarily involved in filtering lymph fluid, the cortex (B) contains B cell follicles, and the medulla (D) contains plasma cells and macrophages. Thus, the paracortex is the specific site of interaction between naïve T cells and activated dendritic cells in lymph nodes.

Correct Answer: D

Rationale: Firstly, Lysozyme is a Microbe-Associated Molecular Pattern (MAMP), not a protein. MAMPs are molecules recognized by the innate immune system to trigger immune responses. Lysozyme is not specific to protecting the eye (A), binding membranes (B), or digesting cell walls (C). Therefore, the correct answer is D.

Correct Answer: C

Rationale: The correct answer is C: Elie Metchnikoff. He is credited with the discovery of phagocytosis, the process in which certain cells engulf and digest foreign particles. Metchnikoff's research in the late 19th century laid the foundation for our understanding of the immune system. A: Edward Jenner is known for developing the smallpox vaccine. B: Louis Pasteur is famous for his work on germ theory and pasteurization. D: Paul Ehrlich is known for his contributions to immunology, such as developing the concept of antibodies and chemotherapy.

Correct Answer: C

Rationale: Edward Jenner's major contribution to immunology was developing the smallpox vaccine. He introduced the concept of vaccination by using cowpox to protect against smallpox. This marked the beginning of modern immunization. Discovering antibodies (A) and proposing innate immunity theory (B) were not directly attributed to Jenner. Discovering the germ theory of disease (D) was later proposed by Louis Pasteur and Robert Koch, not Jenner. Overall, choice C is correct as it aligns with Jenner's groundbreaking work in immunization.

Correct Answer: B

Rationale: The correct answer is B: Plasma cells (derived from B lymphocytes). B lymphocytes are responsible for producing antibodies. When activated, B cells differentiate into plasma cells, which are specialized in secreting antibodies. Neutrophils are primarily involved in phagocytosis, not antibody production. Natural killer cells are involved in killing infected cells, not antibody production. Macrophages are phagocytic cells that present antigens to activate B lymphocytes but do not produce antibodies themselves. Therefore, the correct answer is B as plasma cells derived from B lymphocytes are primarily responsible for antibody production.