Why is the cell theory important?

Cell theory is that to biology as Dalton's atomic theory is to chemistry. As in Dalton's Atomic Theory, we have the atoms as the fundamental unit of a matter and matriculate system, we have the cells as the fundamental and structural unit of the living organisms.[Living organisms can be compared to the matriculate system].

It is one of the most basic principles in the reductionist approach to biology and tries to view the living systems with functional units as cells, the interactions b/w the cells, the intra-cellular processes etc. as it states the following postulates:-

i) Cells are the basic fundamental and structural unit of life. ii) All cells emerge from pre-existing cells.

Almost in all fields of biology, we need some knowledge of cell and cell theory. It has applications in medicine, evolution, microbiology, taxonomy, etc. The basic structures of the cells are studied under the cell theory and in total, it covers the entire courses about cellular structures as well.

For example, in our study of genetic systems, we make use of simpler organisms which is easier to grow and easily available. Then we use the results inferred for some higher or more complex organism (with proper judgement of course!). This is so because of a principle in cell theory which says that all cells have same chemical machinery. In fact most of the cells do share many basic features only finer details vary.