What are the exceptions to cell theory?

Cell Theory:

1. Cell theory is a scientific theory that says, that living organisms are made up of cells.
2. Cells are the basic structural/organizational unit of all organisms.
3. All cells come from pre-existing cells.
4. The Cell theory was first formulated in the mid-nineteenth century by Scheilden and Schwann.

Exceptions to the cell theory.

1. Viruses are non-cellular organisms but are considered living entities.
2. The origin of the first cell during evolution also violates the rules of the cell theory.
3. Mitochondria and Chloroplasts have their genetic material and can reproduce independently from the cell in which they reside so they should be considered cells.
4. RBCs and sieve tube cells do not have a nucleus and other organelles but still are considered living cells.