Infectious agents such as: a. viruses always have a protein coat and a nucleic acid (dna or rna) b. bacteria usually are intracellular (found inside of cells) c. prions are easy to treat because they are denatured proteins d. protozoans are single-celled prokaryotes e. fungi are usually multicellular and large if they infect and cause human disease

A. viruses always have a protein coat and a nucleic acid (DNA or RNA)

Explanation:

Viruses are very small and simple beings, considered parasites for infecting cells of bacteria, protozoa, fungi, plants and animals. Surely you have heard of “flu viruses”, haven't you? Influenza is just one of the diseases caused by viruses that can infect humans. The virus (word that came from the Latin virus = poison / toxin) are simple and infectious little beings, formed basically by a protein capsule that surrounds the genetic material, can be DNA or RNA.

answer: 4

explanation: 8

the cell cycle is the final answer! : )