Cell Theory
- Until microscopes became powerful enough to view individual cells, no-one knew for certain what living organisms were made from
- A scientist called Robert Hooke came up with the term "cells" in the 1660's after examining the structure of cork
- Matthias Schleiden and Theodor Schwann were two scientists who studied animal and plant cells
- In 1837, they came up with the idea that all living organisms are made of cells
- This idea is known as ‘cell theory’
- The cell theory is a unifying concept in biology (meaning it is universally accepted)
- The cell theory includes three main ideas:
- All living organisms are made up of one or more cells
- Cells are the basic functional unit (i.e. the basic unit of structure and organisation) in living organisms
- New cells are produced from pre-existing cells
- Although cells vary in size and shape they all:
- Are surrounded by a membrane
- Contain genetic material
- Have chemical reactions occurring within the cell that are catalysed by enzymes