Question

Are there any exceptions in the Cell theory proposed by Schleiden, Schwann and Virchow? If yes, what are those? [3 MARKS]

Answer 1

Shortcomings of postulates of cell theory:

1. Character of viruses: Cell theory does not explain the nature of a virus as it behaves like a living organism inside a host but does not possess a normal cellular structure.
   
2. Origin of cell: Cell theory does not throw light on how the first living cell originated or how life on earth began as it is said that cells come from preexisting cells.
3. Presence of extra-chromosomal DNA: Mitochondria and chloroplasts are exceptions as they have their own genetic material and can reproduce independently.