Why are modern tetrapod ectotherms restricted to living within roughly 45 degrees latitude of the Equator

One of the main reasons the united states occupied japan after world war ii was that

The vegetation that thrives in the tundra is limited to a. mosses, barley, wheat, and corn. b. coniferous trees. c. dwarf shrubs, mosses, lichen, potatoes, and beans. d. mosses, lichen, algae, and dwarf shrubs.

In the von thunen model of agricultural land use, what is produced closest to the city epicenter? a. dairy, vegetables, and fruits b. field crops, such as corn and wheat c. beef and other animal products d. wood and lumber