Why is the pacific rim a region of earthquakes and active volcanoes?

It's because underneath the pacific rim is tectonic plates that move causing earthquakes, active volcanoes, or both.

within these regions are all the major types of biomes in the world. a biome is a community of animals and plants spreading over an extensive area with a relatively uniform climate. some diverse biomes represented in north america include desert, grassland, tundra, and coral reefs.