There are countless types of plants and animals on Earth, but how do they work? In this episode of Crash Course Biology, we’ll take a bird’s eye view of how multicellular life functions, including how it’s organized, how it regulates itself to maintain homeostasis, and the big question: Why are these living things so wildly complex?br br Introduction: Bizarre Beasts 00:00br Multicellular Organization 1:16br Cell Specialization 3:34br Why We Aren't Unicellular 4:37br Cons of Multicellularity 5:53br Dr.