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

Note taking

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!

Characteristics of Living Things

You are surrounded by life, but how would you define a living thing?

Living things:

1. are made of cells2. Can reproduce3. Use energy to survive4. Have DNA5. Respond to stimuli6. Grow and develop7. Use energy8. Respond to stimuli9. Maintain homeostasis10. 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

Growth of an organism

How do living things grow?

Organisms grow by adding more cells, not by increasing the size of their cells

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

Cells have structure and function

Within the cell, there are parts that each have jobs or functions

These parts or structures are called organelles

Examples of organelles:

The microscope led to the discovery of cells

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 answer? The “Cell Theory” was created!

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 German scientists,

Schleiden and Schwann developed The Cell Theory

Cell TheoryThere are 3 concepts:

1. All living things are composed of cells

2. Cells come from other (pre-existing) cells

3. Cells are the basic structure of living things

Brain Pop!

All about cells!