In 1833, Matthias Schleiden and Theodar Schwann proposed Cells as basic building blocks of all animals and plants.
Their observation led to the formation of Cell Theory.
- All living things are made of cells.
- New cells are formed by cell division.
- Cells contains genetic material that are transferred from parent to offspring.
- Every metabolic reaction takes place inside the cells.
- Hereditary information transferred from one cell to another during cell division.
- All cells have same chemical composition and metabolism activities.
- Tracheids and vessels in plants ,horny cells in animals are dead cells which remain functional.
Exception to Cell Theory
Viruses, viroids, and prions are exceptions to Cell Theory as they lack protoplasm and exist as obligate parasites which are subcellular in nature.
Protoplasm was observed first by Corti. Felix Dujardin in 1835 observed a living juice in an animal cell and called it sarcode.
Purkinje in 1839 coined the term protoplasm for sap inside a plant cell. Hugo Van Mohl in 1846 indicated the importance of protoplasm.
Max Schultze in 1861 found similar features between Protoplasm and Sarcode and proposed a theory called Protoplasm theory.