The document provides information about the tundra biome. It describes the tundra as a cold, treeless plain located mainly in the northern hemisphere. It lists some common animal species in the tundra biome, including polar bears, snowy owls, and arctic foxes, which have all adapted white fur to blend in with the snow. It also describes some plant species that have adapted to the cold, including lichens that are used as food and plants with dark red leaves that absorb more heat from the sun.