Global biodiversity exists in a number of patterns. The largest and most obvious of these is that biodiversity is . a. greatest at the equator and drops as you move farther north or south b. distributed evenly across Earth's surface c. greatest at high elevations but drops as you descend d. higher at the start of a river than at its end

a. greatest at the equator and drops as you move farther north or south

Explanation: Biodiversity is not evenly distributed on Earth. Terrestrial biodiversity is normally greater near the equator, (is richest in the tropics) and it lowers as you move towards the poles.

Tropical forest biodiversity cover less than 10 percent of earth's surface, and contain about 90 percent of the world's species.