A, because they acts as catalysts in the chemical reactions crucial for life within organisms
A virus structure can be on of the following: icosahedral, enveloped, complex and helical. These viruses can appear to in a shape but a closer, more steady look reveals that they are actually icosahedral.
I'd say A, all of the above.
Absence of true roots stems and leaves
The answer is A.<span> the water would all be trapped in the atmosphere. </span>
