AIM: What is the Cell Theory & How was it developed??

Do Now: In one or two complete sentences describe what the following quote tells us about the origin of new life.

Quote: “Fireflies rise from the morning dew,

fish and frogs from a muddy stew, maggot worms from rotting meat and mice shall come from sweat and wheat.”

What is Spontaneous Generation?

- the belief that living things can come from non-living things.

- Was once thought to be true, but is now known to be false!

How was it disproved?- the following scientists with their

combined experiments proved the theory of spontaneous generation to be false & helped develop the Cell Theory.

Who was… Francesco Redi? (1668)

- scientist whose experiments proved maggots did not come from rotting meat.

Who was…Robert Hooke? (1665)

- used a compound microscope to look at cork (from bark of a tree) & he saw empty boxlike structures that he named “cells”.

Who was…Antonie van Leewenhooke? (mid 1600’s)

- used a simple microscope to look at pond water.

- was the first to observe microorganisms in pond water.

Who was…Matthias Schleiden? (1830’s)

Onion cells Elodea cells Cork cells

- studied numerous plant parts under the microscope and declared “ALL PLANTS ARE MADE OF CELLS!”

Who was… Theodor Scwhann? (mid 1830’s)

- Cheek cells Amphibian Blood

- Used a microscope to observe numerous animal tissues and declared “ALL ANIMALS ARE MADE OF CELLS!”

Who was… Rudolf Virchow? (Mid 1830’s)

- observed living cells dividing and declared “ALL CELLS COME FROM OTHER LIVING CELLS!”

These scientists discoveries led to the cell theory…

What is the CELL THEORY???Theory that states…1. All organisms are made of one

or more cells.2. The cell is the basic unit of life

which can perform life processes.

3. All cells come from other living cells.