3. Viruses may harm host cells. A vaccine is one way that infection from viruses can be controlled. Why can't a vaccine help people already infected with a virus?

Autotrophs a.consume their food to get energy b.may use photosynthesis to gain energy c.are also called consumers d.cannot use solar energy

In which state was more than 100 billion tons of coal mined in 2005?

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.