Why is there no such thing as a food chain

Which gas found in the earth's atmosphere greatly impacts the daily range of temperature on earth. a) oxygen b) hydrogen c) nitrogen d) water vapor

The small molecule cyclic amp (camp) takes about 0.2 second to diffuse 10 μm, on average, in a cell. suppose that camp is produced near the plasma membrane on one end of the cell; how long will it take for this camp to diffuse through the cytosol and reach the opposite end of a very large cell, on average? assume that the cell is 200 μm in diameter.

Identify two examples of chemical reactions that you have encountered during the last week. identify an exothermic and endothermic reaction. explain.