The Cell Theory

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.

The Cell Theory

Many scientists contributed to the cell theory

The Cell Theory

3 parts to the cell theory:1. The cell is the basic unit of life2. All living things are made of cells3. Cells come from pre-existing cells

Anton van Leeuwenheok (1632-1723)

He invented the first microscope.Dutch scientist who was the first to see bacteria and protists.

Leeuwenhoek’s Microscope

Robert Hooke (1635-1703)

He observed that cork has small regular boxes in it that he called “cells”.

Hooke’s cork cells

Theodor Schwann and Matthais Schleiden stated that all living

things are made of cells. (1839)

Matthais Schleiden (plants)

Theodor Schwann (animals)

Rudolph Virchow (1821-1902)

German scientist who discovered that all cells come from pre-existing cells.

The Cell Theory

Continued advances in microscopy allowed observation of cell organelles and structure.

Electron Microscopes

Scanning Electron Microscope (SEM): bounces electrons off of a whole gold-coated sample to create vivid 3-D images

Transmission Electron Microscope (TEM): bounces electrons off of a sliced sample to create very detailed images

Questions...

Who used the first microscope?Who said that plants were made of cells?Who coined the term “cell”? Who said that all animals were made of cells?Who said that cells must come from existing cells?

State the cell theory...

The cell is the basic unit of structure.

The cell is the basic unit of function.

All cells arise from pre-existing cells.