Answer:
Birth rate, death rate, immigration and emigration can all effect the population numbers.
There are a few types of active transport, but if we're talking about the sodium potassium pump for example, we know that for movement of this type, we need energy in the form of ATP (adenosine triphosphate) which has also been called the energy currency of the body. This gets broken down and then enables for different substances to move in and out of the cell membrane (this is just one example of active transport).
Explanation:
polar bear depend on ice so if it gets really hot out of a sudden the melt will melt away and it would be harder for them to live. and for grizzly bears if gets cold all out of the sudden the rivers where they get food turns to ice they'll food which is what they depend on (fish) will die and without food they'll die too.
