Question

multiple choice question viruses are considered to be ______ parasites because they multiply by invading a specific host cell and instructing its genetic machinery to make more viruses. facultative intracellular obligate extracellular obligate intracellular facultatively extracellular

Explanation:

Viruses are obligate intracellular parasites as they cannot multiply outside a host cell and require the host - cell's machinery to replicate. They are not facultative intracellular (which can live inside or outside cells) or extracellular (as they need an intracellular environment to multiply).

Answer:

Obligate intracellular