The document discusses the tundra biome and some of its key features. It notes that the tundra is one of the coldest biomes and is found in areas around the Arctic, including Alaska, Canada, and northern Russia. It lists several plant and animal species common to the tundra, such as arctic moss, arctic willow, polar bears, arctic foxes, and snow leopards. The document also illustrates how extinction of one species, such as deer, could negatively impact other species higher on the food chain, like snow lions, demonstrating the interconnectedness of ecosystems.