Explore the fundamentals of adaptive immunity in this comprehensive biology lecture designed for MCAT, DAT, and NCLEX preparation. Delve into the distinctions between B-cell (humoral) and T-cell (cellular) immunity, and gain insights into various immune cells including lymphocytes, neutrophils, basophils, eosinophils, macrophages, and natural killer cells. Examine the historical context of immunology, understand T-lymphocyte functions, and discover the clinical implications of adaptive immunity. Enhance your understanding of this crucial aspect of the immune system through detailed explanations and examples provided in this 23-minute educational video.