Question

Which is correct about cell theory in view of current status of our knowledge about cell structure?

• A. It needs modification due to discovery of sub cellular structure like chloroplasts and mitochondria.
• B. Modified cell theory means that all living beings are composed of cells capable of reproducing.
• C. Cell theory does not hold good because all living being do not have cellular organization (e.g., viruses)
• D. Cell theory means that all living objects consists of cells whether or not capable reproducing.

Answer 1

The correct option is C Cell theory does not hold good because all living being do not have cellular organization (e.g., viruses)

Cells theory proposed by 'Schwann and Schleiden' states that all living organisms whether animals or plants are made up of cells and have similar organization. It is the unit of structure and function. Exception to cell theory are cellular organisms, i.e., lacks cellular organizations. Moreover, coenocytic forms like Paramecium, Rhizopus, have more than one nuclei and are exceptions to cell theory.