| There were many scientists from 1665 up to 1839 who helped confirm the idea of cells and what they do. |
| Table 1: Scientists who contributed to the study of cell theory | |
|---|---|
| NAME | CONTRIBUTION |
| Robert Hooke | English polymath who introduced the idea of a “cell”. While observing thin pieces of cork under a microscope, he saw small rooms which he named cellula (Latin for small room). |
| Anton van Leeuwenhoek | Known as the father of microbiology. He observed single-celled organisms under the microscope, which he called animacules, later known as bacteria. |
| Robert Brown | A Scottish botanist who discovered the nucleus while studying plant cells. |
| Mathias Schleiden | A German botanist who proposed that all plants are made of cells and that cells are the basic unit of life in plants. |
| Theodor Schwann | A German physiologist who extended Schleiden’s ideas to animals, concluding that all animals are made of cells. |
| Rudolf Virchow | A German physician who opposed spontaneous generation and stated that all cells come from pre-existing cells (Omnis cellula e cellula). |
| Table 2: Cell Theory’s Tenets | |
|---|---|
| Tenet | Description |
| Cells are the basic unit of life | Each cell is independent, self-sustaining, and capable of performing all metabolic functions necessary for life. |
| All living things are made up of cells | All organisms are composed of cells. Viruses are not considered living because they are not made of cells. |
| All cells come from pre-existing cells | Cells reproduce to form new cells, ensuring continuity of life. |
| DNA is passed on during cell division | Genetic material is transferred from parent cells to daughter cells, explaining inherited traits. |
| All cells are fundamentally the same within a species | Organisms of the same species have similar cellular structures, which helps in classification. |
| Energy flow occurs within cells | Cells carry out biochemical reactions such as photosynthesis and respiration to maintain metabolism. |