What distinguishes a virus from a bacterium?

Explanation:

Viruses are tinier than bacteria. In fact, the largest virus is smaller than the smallest bacterium. All viruses have is a protein coat and a core of genetic material, either RNA or DNA.

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.