This lecture on Classification of Organisms explains biodiversity as the variety of living things, from plants and animals to microorganisms. It covers key terms like extinct and endangered species, habitats, pollution, game reserves, and national parks, and highlights the importance of biodiversity in providing food, clean air, medicines, and ecological balance. Students learn ways to protect biodiversity and explore examples of unique animal features, such as sharks’ cartilage skeletons, zebras’ stripes, and elephants’ large ears. The lecture also discusses causes of extinction, gives examples of extinct and endangered species locally and globally, and concludes with activities and Q&A to stress the need for conservation.