Cell theory - SS1 Biology Lesson Note

The cell theory was developed in the mid-19th century by Matthias Schleiden, Theodor Schwann, and later refined by Rudolf Virchow. Their combined contributions laid the foundation for understanding the cellular basis of life and revolutionized the field of biology. The cell theory is a fundamental concept that underpins our understanding of how living organisms are organized and function.

Cell theory is a fundamental principle in biology that describes the basic unit of life and the organization of living organisms. It consists of three main principles:

1.     All living organisms are composed of cells: According to cell theory, cells are the smallest structural and functional units of life. Every living organism, whether it is a single-celled organism or a complex multicellular organism, is composed of one or more cells. Cells are the building blocks of life.

2.     Cells are the basic units of structure and function: Cell theory states that cells are responsible for carrying out all the essential functions necessary for the survival and functioning of living organisms. Each cell performs specific tasks and contributes to the overall functioning of the organism. Cells have different structures and functions based on their specialized roles within the organism.

3.     Cells arise from pre-existing cells: Cell theory proposes that new cells are generated through the division of pre-existing cells. This concept, known as cell division, is the basis for growth, development, and reproduction in organisms. Cells can replicate their genetic material and divide into two or more daughter cells, each of which has the potential to grow and divide further.