Question #c9d9f

1 Answer
Nov 6, 2017

Viruses cannot survive or reproduce independently.So they are considered parasites.


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.
Once inside a cell, viruses have genes for usurping the cell’s energy-generating and protein-synthesizing systems.
In addition to their intracellular form, viruses have an extracellular form that carries the viral nucleic acid from one host cell to another. In this infectious form, viruses are simply a central core of nucleic acid surrounded by a protein coat called a capsid.