AP BIOLOGY

Detailed explanation-1: -Permafrost is soil that is permanently frozen. Permafrost is a permanently frozen layer on or under Earth’s surface. It consists of soil, gravel, and sand, usually bound together by ice. Permafrost usually remains at or below 0°C (32ºF) for at least two years.

Detailed explanation-2: -Where Is Permafrost Found? About a quarter of the entire northern hemisphere is permafrost, where the ground is frozen year-round. It’s widespread in the Arctic regions of Siberia, Canada, Greenland, and Alaska-where nearly 85 percent of the state sits atop a layer of permafrost.

Detailed explanation-3: -Tundra winters are long, dark, and cold, with mean temperatures below 0°C for six to 10 months of the year. The temperatures are so cold that there is a layer of permanently frozen ground below the surface, called permafrost. This permafrost is a defining characteristic of the tundra biome.