During physical exertion, animals begin to respire heavily. what is the purpose of the heavy breathing?

Amines amides and amino acids are categories of

The serengeti plains are part of the african savanna ecosystem and are home to a variety of different species of plants and animals. the serengeti plains experience a seven-month period of seasonal drought each year, during which the ecosystem receives only four inches of rain and the availability of some resources becomes very scarce. which type of limiting factors does the seasonal drought in the serengeti plains affect?

Some substances but not other can cross the (blank) membrane of a cell