The three fundamental propositions of classical cell theory are that the cell is the most basic unit of life, all life is made up of cells and cells are formed only by other cells. Each tenet of this theory is important to understanding the way living things function on every level.Continue Reading
The first proposition, that the cell is the most basic component of living things, can be observed directly. Single-celled organisms are well known and may comprise the bulk of Earth's living biomass. Any unit, such as a tissue, that can be broken down still further cannot be regarded as basic. Units more simple than a cell, however, cannot truly be said to be alive. A cell's organelles, for example, function only in the context of their cellular environment.
From this it follows that all life must be made up of cells. Cells build tissues, tissues make organs, organs are organized into systems and these systems make up the bodies of organisms. Across the domains of life, whether eukaryotic or prokaryotic, all living things can be described in terms of their cells.
Finally, the cell theory posits that the origin of a living cell must be a result of the action of another living cell. Cells do not spontaneously form, and they are too complicated to self-assemble.Learn more about Cells
The modern cell theory states that living organisms are made of cells, that all cells come from other cells and that cells are the most basic life form. As scientific advancements are made, definitions of theories, like the cell theory, are updated. The modern cell theory is not the same as cell theory of the past.Full Answer >
Non-living things are not composed of cells, as cells are the smallest unit of life. Small organisms such as bacteria and protists are only composed of a single cell, but are alive.Full Answer >
Cell biology is the study of cell structure and function, based on the concept that the cell is the basic unit of life. Understanding cells permits a detailed understanding of the tissues and organisms that cells make up.Full Answer >
Cell biology is a discipline that views the cell as the fundamental unit of life and studies cell structure and function. It seeks to elucidate properties of cells that are universal to all or most cells as well as unique properties that are limited to a small subset of specialized cells.Full Answer >