Question

___________ are an exception to cell theory.
(А) Bacteria
(B) Fungi
(C) Viruses
(D) Lichens

Answer 1

Hint: Cell theory was proposed and defined by botanist Matthias Schleiden and zoologist Theodor Schwann in the 1830s. They state that: The basic unit of life in any living organism is a cell. The organelles are present in the eukaryotic cells, while prokaryotic cells do not contain them.

Complete answer:
We had known and found the meaning of the cell theory. However, on the other hand, we should know that some of the organisms present on the earth do not follow these rules. This makes them exceptions.
As the theory was for the living organisms only we will match this with given options. The organisms which are not considered as living will show exceptions.
Bacteria :- they are the members of kingdom Monera. They have their own machinery. They are replicated by their own and have their own genetic material so they are considered as living and are applicable in cell theory.
Fungi :- the cell wall of fungi is made up of chitin. The fungi replicate and divide by their own machinery. They do not take machinery of their own but are also living outside the body of the host. So they are living and are applicable to cell theory.
Viruses :- Viruses are an exception to cell theory as they are not made up of cells/ They are composed of nucleoprotein tiles, therefore, they are not considered either living or non-living. Other exceptions are coenocytic organisms like Rhizopus
Lichens :- when fungi live in symbiotic association with algae it is termed as lichens. They are living organisms and a good pollution indicator so they are applicable in cell theory.

Our required option is C that is viruses.

Note: Another exception of the cell theory is Coenocytic organisms. The Coenocytic organisms like Vaucheria and fungi including Rhizopus or bread mould belong to the phylum of Phycomycetes. These are known as filamentous organisms with incessant protoplasm and considerable nuclei numbers. The filament is not separated into cells, with the help of a single nucleus that experiences division occasionally so they are not living.