1. The Cell Theory – a timeline Late 1500’s: -first lenses used in Europe -used to determine cloth quality (weave and precision) -combos of lenses gave better view Early 1600’s:Leeuwenhoek uses microscope to study nature

2. Early 1600’s Leeuwenhoek first to view pond water organisms First to see living microscopic orgs Made careful sketches Early 1600’s

3. Robert Hooke ( 1665) Used light microscope to look at thin slices of plant tissues -- cork Looked empty, like monk’s chamber Called tiny chambers “cells”

4. Matthias Schleiden 1838 German Botanist (plants) All plants looked at were made of cells, so concluded: “All plants are made of cells.”

5. Theodore Schwann -- 1839 German scientist who studied animals -- zoologist Saw that all animals he studied were cellular so concluded: “ All animals are made of cells.”

6. Rudolf Virchow -- 1855 German physician who studied cell reproduction “Where a cell exists, there must have been a preexisting cell…..”

7. The Cell Theory All living things are composed of cells Cells are the basic units of structure and function in living things New cells are produced from existing cells