Correct Answer: Option A
Explanation:
The skin and mucous membranes act as primary physical barriers in innate immunity, preventing pathogen entry. Phagocytosis by macrophages and neutrophils is a non-specific (innate) cellular defense mechanism, not a specific immune response. Memory B and T cells are produced during the primary specific immune response and provide rapid, long-lasting immunity upon re-exposure. Thus, statements 1 and 3 are correct.
This question belongs to:
Science
Biology
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