CELL THEORY – One Of The Basic Principles In Biology
CELL THEORY – In this lesson, we will now talk about the cell theory, one of the basic principles of biology with some other things to know.
Cell Theory
The principle states that:
- All living organisms are composed of cells.
- The cell is the basic unit of life.
- Cells arise from pre-existing cells.
It basically means that cells are the basic unit of life and all organisms, may it be a single cell (unicellular) or multiple cells (multicellular), are made of cells, and new cells will be born from the pre-existing cells.
There is a modernized version of this therory, which states that:
- Energy flow occurs within cells.
- Heredity information (DNA) is passed on from cell to cell.
- All cells have the same basic chemical composition.
Basics About Cells
Again, cells are the basic unit of life. There are two kinds of cells:
- Prokaryotic – cells that has no nucleus. This includes animal and plant cells.
- Eukaryotic – cells that have a true nucleus
The parts of a cell are called organelles and each organelle has its own function.
Reproduction
In the case of eukaryotic cells, they grow and reproduce in a process called the cell cycle, where at the end of the cycle, they divide through either of the two processes called “mitosis” or “meiosis“. In prokaryotic cells, on the other hand, reproduce asexually in a process called binary fission.
Cell Processes
- Endocytosis and Exocytosis – processes that involves active transport. Endocytosis involves internalizing and digesting substances, while exocytosis is the expulsion of the digested substances.
- Cell Migration – A vital process that deals with the development of tissues and organs.
- DNA Replication and Protein Synthesis – These two processes deals with several processes including chromosome synthesis and cell division to occur.