AP BIOLOGY

Detailed explanation-1: -Viruses mutate and some have not been discovered. Viruses are not filterable. Two noncellular agents, smaller than viruses, are the infectious proteins called and the infectious RNA strands called .

Detailed explanation-2: -Final Answer: Viruses do not infect bacteria, fungi and algae is not the correct statement.

Detailed explanation-3: -The term “filterable viruses” was introduced in the late nineties of the preceding century, to denote a group of disease producing agents, which seemed to differ from other forms of living matter in their ability to pass through earthenware filters having a pore diameter smaller than the smallest bacteria then known.

Detailed explanation-4: -All viruses are obligate parasites; that is, they lack metabolic machinery of their own to generate energy or to synthesize proteins, so they depend on host cells to carry out these vital functions.

Detailed explanation-5: -What is the significance of viruses being recognized as “filterable"? Early researchers found when infectious fluid was passed through filters designed to trap bacteria, the filtrate remained infectious. This proved an infection could be caused by a cell-free fluid containing agents smaller than bacteria.