Download recognize that according to cell theory all organism are composed of

7.12F: recognize that according to cell theory all organism are composed of cells and
cells carry on similar functions such as extracting energy from food for life
You will need to take a few notes, listen
and I will tell you when to write down
information.
 Title your page now:
“Cell History and Theory”

To help guide your note taking, make sure
to write down what is in red. You can of
course, add more if you need!
Note taking
Characteristics of
Living Things
You are surrounded by life, but how would
you define a living thing?
Living things:
1. are made of cells
2. Can reproduce
3. Use energy to survive
4. Have DNA
5. Respond to stimuli
6. Grow and develop
7. Use energy
8. Respond to stimuli
9. Maintain homeostasis
10. Evolve over time
All living things are made of cells
A cell is the simplest structure of living
things
 If an organism is unicellular, all functions
of life happen within that one cell.
 If an organism is multicellular, the
different cells have different jobs and they
all work together

Simple Organisms

Some organisms are simple: they are not
particularly specialized and complicated in
structure (think microscopic)
For example: Bacteria, Achaea, most
protists (unicellular)
Complex Organisms
Some organisms are more complex:
 “Complex” means that different parts of the
organism performs different functions.
Examples: humans, dogs, fish,
mushrooms, oak trees

How do living things grow?
 Organisms grow by adding more cells, not
by increasing the size of their cells

Growth of an organism
What do cells look like?
The word “cell” is Latin for “small room”
 They look as varied as the organisms they
build (make up)

Red Blood cell
Stem Cell
Brain cell
Plant cell
Within the cell, there are parts that each
have jobs or functions
 These parts or structures are called
organelles
 Examples of organelles:

Cells have structure and function

1665 – Robert Hooke published a book that
described the cell
1. He looked at cork (a plant) under the
microscope (30x)
2. He noticed little compartments, which
he named “cells” because they resembled the
little rooms that monks lived in
The microscope led to the discovery of cells

1675 – Anton Van Leeuwenhoek is
considered the father of microscopy because of
the advances he made in microscope design and
use.
1. He looked at pond water under the
microscope (300x) and noticed that the water
was full of moving living things
2. He made the most advanced microscope
of his time
The microscope
led to the
discovery of cells
 With
the invention of the microscope
and the contributions of many
scientists, a very important question
was answered in the 1850’s. The
question was:
 Where
do cells come from?
The answer?
The “Cell Theory” was created!
The German scientists,
Schleiden and Schwann
developed The Cell Theory
Cell Theory
There are 3 concepts:
1.
2.
3.
All living things are composed of
cells
Cells come from other (preexisting) cells
Cells are the basic structure of
living things
Brain Pop!

All about
cells!