What effect does oxygen have on kelp

What must be true for natural selection to heppen

Melting glaciers is a serious threat to the environment what is the possible consequence of melting glaciers on polar bears?

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?