Transcript Cells - Weebly

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Cell Games & Activities
Link
W
+ hat
is a Cell?

Cells are the structural and
functional units of all living
organisms.

Some organisms, such as bacteria,
are unicellular, consisting of a single
cell. Other organisms, such as
humans, are multi-cellular, or have
many cells—an estimated
100,000,000,000,000 cells!

Each cell is an amazing world unto
itself: it can take in nutrients, convert
these nutrients into energy, carry out
specialized functions, and reproduce
as necessary.

Even more amazing is that each cell
stores its own set of instructions for
carrying out each of these activities.
The discovery of
cells would not have
been possible
without the
microscope.
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Microscopes have
been improved in
many ways over the
last 400 years.
1590—Hans
Janssen and his
son Zacharias
were Dutch
eyeglass makers.
They made the
first compound
microscope. It
was a simple tube
with a lens on
each end.
The Microscope—
Improvements Over Time
R
+obert Hooke
In 1660, an Englishman, Hooke,
improved upon the compound
microscope made by Anton van
Leeuwehn Hoek. Hooke’s
microscope added a stand and
had oil for a flame to light the
specimen.
First compound light microscope.
He first observed a cork, and
called the structures that he
observed “cells,” because they
looked like a line of prison cells.
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Anton van
Leeuwen Hoek
Leeuwen Hoek was a Dutchman
that worked with magnifying
lenses. He was making
microscopes before Hooke, But, it
was his discovery in 1683 that
gave him the name of Father of
Microbiology. He was the first
person to see many one-celled
organisms. He gave the first
detailed descriptions of bacteria,
protozoa, red blood cells and
capillary circulation. He created
over 400 different types of
microscopes.
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1886 Modern
Compound Light
Microscope invented
by three German
scientists. It magnified
specimens up to 1,000
times.
Ernst Abbe
Carl Zeiss
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1931 German physicist, Ruska,
created the first electron microscope.
It makes images by sending electrons
through a thinly sliced specimen. It
can magnify up to 500,000 times.
Ernst Ruska
1931 Electron Microscope
Threedimensional
image of a
flower.
1965 The first three-dimensional
microscope is used that sends a
beam of electrons over the
surface of a microscope. It can
magnify up to 150,000 times. It
was developed by Prof. Sir
Charles Oakley and Gary Stewart
of Great Britain.
1965 - Scanning Electron
Microscope
Gerd Binnig and Heinrich Rohrer invented the
scanning tunneling microscope that gives threedimensional images of objects down to the atomic
level. Binnig and Rohrer won the Nobel Prize in
Physics in 1986. The powerful scanning tunneling
microscope is the strongest microscope to date.
Early Contributions to the
Understanding of a Cell
Because of the developments and
improvements of the microscope, the
+following scientists were able to
contribute to the discovery and
understanding of the cell, thus
developing The Cell Theory.
+ obert
R
Hooke
Anton Van
Leeuwen
Hoek
1665: The first person to see
cells. He was looking at cork
and noted that he saw "a great
many boxes.”
•
1673: Observed living cells in
pond water, which he called
“animalcules.”
•
T
+ heodor
Schwann
1839: A German zoologist who
observed that the tissues of
animals had cells.
•
M
+ atthias 1845: A German botanist who
observed that the tissues of
Schleiden plants contained cells.
•
R
+ udolf
Virchow
1850: A German pathologist, and
anthropologist widely credited for
his advancements in public health.
•
Known as the "father of
pathology." He reported that every
living thing is comprised of vital
units, known as cells.
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He also predicted that cells come
from other cells. His scientific
contribution to The Cell Theory
explained the effects of disease on
the body.
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He also developed a standard
method of autopsy procedure.
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T
+ he Cell
Theory
•1. All
cells arise from preexisting cells.
•2. The
cell is the basic unit of
structure and function. It is the
smallest unit that can perform
life functions.
•3. Every
Why is it called a
theory and not a fact?
living organism is
made of one or more cells.
+ hat Is A
W
Theory?
• Newton’s Theory of Gravity
• Newton’s Theory of the
Motion of Planets
• Einstein’s Theory of
Relativity
• Germ Theory of Disease
• Cell Theory
• Theory of the Motion of Land
Masses (Plate Tectonics)
 As
used in science, "theory" does
not mean the same thing as it does
in everyday life. A theory is not a
guess, hunch, or speculation. It is
much more.
 A theory
is built upon one or
more hypotheses and upon
evidence. The word "built" is
essential, for a theory contains
reasoning and logical connections
based on the hypotheses and
evidence.
 Scientists,
world-wide, classify
data and observations so that
others in the scientific community
can validate their findings.