Transcript Anton van Leeuwenbock

CELL THEORY TIMELINE
Understanding Cells
Have you ever looked up at the night sky
and tried to find other planets in our solar
system? It is hard to see them without
using a telescope. This is because the
other planets are millions of kilometers
away. Just like we can use telescopes to
see other planets , we can use
microscopes to see the basic unit of all
living things, cells.
Understanding Cells
• But people didn’t always know about cells.
Because cells are so small, early scientists had
no tools to study them. It took hundreds of
years for scientists to learn about cells.
• More than 300 years ago, an English scientist
named Robert Hooke built a microscope. He
used the microscope to look at cork cells ,
which are found in the bark of the Cork Oak
tree. What he saw looked like the openings in a
honeycomb. The openings reminded him of
the small rooms monks stayed in so he named
the cells.
Understanding Cells
• After Hooke’s discovery, other
scientists began making better
microscopes and looking for cells in
many other places such as in pond
water and blood. The newer
microscopes enabled scientists to see
different structures inside the cells.
Understanding Cells
• Matthias Schleiden , a German scientist, used
one of the new microscopes to look at plant
cells. Around the same time, Theodor Schwann
used a microscope to study animal cells.
Schleiden and Schwann realized that plant and
animal cells have similar features that carry on
similar functions, such as extracting energy
from food and eliminating wastes. From this
evidence, Schleiden and Schwann concluded
that cells are the basic unit of life.
Understanding Cells
• Almost two decades later, Rudolph Virchow, a
German doctor, proposed that all cells come
from existing cells. The observation made by
Schleiden, Schwann and Virchow were
combined into one theory. The cell theory
states that all living things are made of
one or more cells, the cell is the
smallest unit of life, and all new
cells come from pre-existing cells.
ROBERT HOOKE
• 1655
• First observed cells of cork under a
very primitive microscope.
• Named them “cells” because they
reminded him of the cells that
monks lived in
• Word cell is Latin for small
compartment
Anton van Leeuwenbock
• 1670 - Looked at
pond water under a
microscope and was
the first to see living
cells
Anton van Leeuwenbock
• 1683
• Sees first protozoa
and bacteria under a
microscope
Robert Brown
• 1833 English botanist
nucleus in plant
cells
Matthias schleiden
1838 –
First to determine
that all plants are
made of cells
•
•
•
•
Theodore schwann
1839
Discovered that all animals are made of cells
Responsible for discovery of enzyme pepsin
Wrote the first cell theory that stated
– Cells are organisms and all organisms are made of
at least one cell
– The cell is the basic unit of structure of all
organisms
Albrecht von kollicker
• 1840
• Swiss embryologist who
first discovered that eggs
and sperm are cells
Carl heinrich braun
• 1845
• Botanist who reworked
Schwann’s cell theory
stating that cells are the
basic unit of life
Rudolph virchow
• 1855
• Concluded that all cells are
made form existing cells
• New cells form from the
division of existing cells
• Called the Father of
Pathology