Question

Why does Viruses form exception to cell theory?

Answer 1

Cell theory states that:
1. All living things are made up of cells.
2. A cell is the basic structural and functional unit of a life.
3. New cell arises from preexisting cells
Viruses are not true cells. They have a simple coat of protein only. They do not contain any cell organelle like mitochondria, ribosome etc. Viruses are alive only until they are inside their host cell. They are considered to behave dead when outside the host cell. Hence, Viruses are an exception to cell theory.