Transcript Intro to the Cell - Gwinnett County Public Schools

Intro to the Cell - History
Pgs. 16-22 in Cell Book
Robert Hooke – 1665
First to describe “cells”
while observing cork
under a microscope.
Wrote Micrographia,
the first book
describing observations
made through a
microscope
There is no official
portrait of Hooke
Spontaneous Generation
• People believed that living things
came from non-living things.
• They noticed flies on rotting
meat and assumed that the flies
came from the rotting meat itself.
• 1668 - Italian Francesco Redi set
out to prove that life only comes
from life.
Francesco Redi
Francesco Redi’s experiment
Click on the link above to recreate his experiment
Anton van Leeuwenhoek
1674 - Was the first to
see bacteria under a
microscope
Made many
advancements in the
field of microscopy by
making better
microscope lenses and
detailed observations
Schleiden, Schwann, & Virchow
1838, 1858
Cell Theory:
• All life forms are made from one or more cells
• The cell is the smallest form of life
• Cells only arise from pre-existing cells
– "Omnis cellula e cellula"
Louis Pasteur - 1864
French Scientist Louis Pasteur
also worked to disprove
spontaneous generation
Said that bacteria came from
other bacteria.
Microorganisms floated in
the air around us
They would land and multiply
when conditions were
favorable
Pasteur’s experiment
Click on the link above to recreate his experiment
Compound Light Microscopes
Uses lenses (two or more =
compound) to magnify a specimen
many times larger than normal size
Magnifies the specimen 10x, 40x,
100x, and so forth
Has a light source to illuminate the
specimen
Specimen is placed on a slide along
with a drop of water, very thin section
so that light can pass through