What are the three main ways that a biome is classified?

Are the earth's ocean floor and continents the same age geologically? why or why not?

Which part of the neuron below is indicated by the arrow, and what is its function? hormones send chemical signals throughout the body to regulate other body processes. hormones are chemical signals that are sent throughout the body to regulate other body processes. hormones send electrical signals throughout the body to regulate other body processes. hormones are electrical signals that are sent throughout the body to regulate other body processes.

Up to what percentage of the world's flora consisted of cycads during the triassic period? 100% 75% 50% 20%