According to cell theory, what do these four organisms have in common? a) they are made of one or more cells. b) they must undergo sexual reproduction. c) they have a nucleus or control center. d) they require carbon dioxide to produce food.

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.