Question

select the description that would represent a pathogen that would be considered a virus.
a. genetic material that is surrounded by a protein coat and uses a host cell to reproduce
b. a single - celled organism that infects animals and plants
c. an organism that feeds off others in order to gain its nutrients
d. a single - celled organism that can be a parasite

Explanation:

Viruses are non - cellular entities. They consist of genetic material (either DNA or RNA) surrounded by a protein coat (capsid). Viruses are obligate intracellular parasites, which means they cannot reproduce on their own. They must use a host cell's machinery to replicate.

• Option A: This description matches the characteristics of a virus (genetic material + protein coat + use of host cell for reproduction).
• Option B: A single - celled organism that infects animals and plants could be a bacterium (e.g., some bacteria cause plant and animal diseases), not a virus (viruses are non - cellular).
• Option C: An organism that feeds off others for nutrients could be a parasite (e.g., some protozoans, fungi), but not specifically a virus.
• Option D: A single - celled organism that can be a parasite is more likely to be a protozoan (e.g., Plasmodium, which causes malaria) or a bacterium, not a virus.

Answer:

A. genetic material that is surrounded by a protein coat and uses a host cell to reproduce