Biomes

Freshwater

What percentage of the earth's water is freshwater? How much of this freshwater is drinkable?

2.5% is freshwater, 1% of freshwater is drinkable.

Marine

Is coral classified as an animal or a plant? Is it both?

Coral is an animal. It is built up of several animals called polyps, which cling together on rocks or dead polyps to create coral.

Desert

Why is a cold desert considered to be a desert if it is known to have heavy rainfall and snow?

I couldn't find much information on this question. What I have gathered is that cold deserts, like regular deserts, can become extremely hot during the summer and are known to be very dry. Cold deserts are often higher in altitude that regular deserts. I believe it is still considered to be a desert because it is usually very flat and barren.

Forest

Why do tropical forests not have much change in weather? Is it just the overall density of the trees doesn't allow much change in weather to be felt or is it the location itself?

I couldn't find much information on this question. From what I gathered, the weather doesn't change that much because the tree cover is so thick that a consistent amount of sunlight is let through, which usually isn't much. There are usually several interesting plants and animals where the sunlight does shine through.

Grassland

Is the only difference between temperate grasslands and savannas just a slight change in conditions, (exp: savannas need just a bit more rainfall than temperate grasslands do)?

The main difference is that savannas are just abut always in warm climates whereas a temperate grassland is often, but not always, in a warm climate. Also, savannas need more water than a temperate grassland does.

Tundra

How cold does the Alpine tundra get, what is the exact difference between the temperatures of the Alpine and Arctic tundra?

The Alpine tundra can be anywhere from 10 degrees Fahrenheit to 50 degrees Fahrenheit during the summer. The Arctic tundra is never hotter than 50 degrees Fahrenheit.