Final answer:
Option d) Cells are not capable of reproduction is not a principle of the cell theory as all cells do have the ability to reproduce. Other principles such as cells as the basic units of life, all living things made up of cells, and cells arising from other cells, are all foundational elements of the cell theory.
Step-by-step explanation:
The principle of the cell theory that is not true is option d) Cells are not capable of reproduction. In fact, one of the key components of the cell theory is that all cells are capable of reproduction, essentially that all cells arise from pre-existing cells. The correct principles, which are included in the cell theory, are as follows:
- Cells are the basic units of life.
- All living things are made up of cells.
- Cells can only be produced from other cells.
Cells are indeed the fundamental building blocks of all living organisms, and they possess the ability to reproduce, which is vital for the continuation of life.