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 subcellular structures 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 beings do not have cellular organisation (e.g. viruses)
D. Cell theory means that all living objects consist of cells whether or not capable of reproducing

Answer 1

Correct Answer - C
Cell theory proposed by Schleiden and Schwann states that all living organisms whether animal or plants are made up of cells and have similar organisation. It is the basic unit of structure and function . Exception to cell theory are the viruses mycoplasma, viroids, bacteria which are acellular organisms, i.e . lacks cellular
organisations. Moreover, coenocytic forms like Paramecium, Rhizopus, have more than one nuclei and are exception to cell theory.