1. The Cell Theory SOL BIO 2a

2. The Cell Theory The development and refinement of magnifying lenses and light microscopes made the observation and description of microscopic organisms and living cells possible.

3. The Cell Theory Many scientists contributed to the cell theory

4. The Cell Theory 3 parts to the cell theory: 1. The cell is the basic unit of life 2. All living things are made of cells 3. Cells come from pre-existing cells

5. Anton van Leeuwenheok (1632-1723) He invented the first microscope. Dutch scientist who was the first to see bacteria and protists.

6. Leeuwenhoek’s Microscope

7. Robert Hooke (1635-1703) He observed that cork has small regular boxes in it that he called “cells”.

8. Hooke’s cork cells

9. Robert Brown (1773-1858) Scottish botanist who noticed that all cells have a dark region that he called a “nucleus”

10. Theodor Schwann and Matthais Schleiden stated that all living things are made of cells. (1839) Matthais Schleiden (plants) Theodor Schwann (animals)

11. Rudolph Virchow (1821-1902) German scientist who discovered that all cells come from pre-existing cells.

12. The Cell Theory Continued advances in microscopy allowed observation of cell organelles and structure.

13. Electron Microscopes Scanning Electron Microscope (SEM): Scanning Electron Microscope (SEM): bounces electrons off of a whole gold- coated sample to create vivid 3-D images Transmission Electron Microscope (TEM): Transmission Electron Microscope (TEM): bounces electrons off of a sliced sample to create very detailed images