Transcript Cell - Garnet Valley School District

Chapter 1: Cells
Section 1
Life Science
Do you Remember?

All living things are organized…

A Cell is the basic unit of structure in
living things.
www.earthlife.net/cells.html
Organisms depend on
cells


Unicellular- single-celled organism
Multicellular- organism made up of
more than one cell
Modern Microscopes
Recall:
 “What are some examples of
microscopes?”
The History of the Cell

Scientists used their new invention, the
microscope, to discover microscopic
organisms.

Using the microscope, scientists were
able to explore the world of cells…
Discovery of Cells

In 1665, Robert Hooke used a
compound microscope to look at a thin
slice of cork.
– Observed empty boxes that he named
“Cells”
– Cork came from an Oak Tree
Hooke’s Discovery
Discovery of Living Cells

Late 1600’s, Anton
van Leeuwenhoek
used a glass bead to
look at pond water.

First to discover
living single-celled
organisms
Development of the
Cell Theory

Cell Theory States:
1. All Living Things are made up of one or
more cells.
2. Cells are the basic units of structure and
function in all living things.
3. All cells come from cells that already
exist.
Lab Activity

You will pretend you are Robert Hooke
as you look through the microscope at
a piece of cork and draw what you are
viewing at the 3 different powers.
Lab Activity

Pre-Lab Questions:
– What type of Microscope do we use in
lab?
– What are the three objective lenses on
the Microscope?
– Why must you be careful when using the
High-Power Objective Lenses?

Louis Pasteur studied microorganisms
and the cell theory…

Observed that spoiled milk contained
BACTERIA!
Pasteur

Bacteria are single-celled organisms
that can cause disease.

Developed Pasteurization which is a
process that uses heat to kill bacteria.
Bacteria and
Spontaneous Generation

So we know… Bacteria are singlecelled organisms that can cause
disease.

Where can bacteria be found???

Pasteur found microorganisms
everywhere (air, water, soil, blood)

While Pasteur was conducting
research studies, scientists thought
bacteria grew from nonliving
materials… or they …

Spontaneously Appeared !!!!
(Spontaneous Generation)

Spontaneous Generation- the idea
that bacteria grew from nonliving
materials

What do you think???

What do you know???
Look at Text Pg 15

Disproved by …Pasteur’s Experiments

He showed that cells come from other
cells… and confirmed the cell theory