KEY CONCEPT Cells are the Basic unit of life.

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KEY CONCEPT Cells are the Basic unit of life. The cell theory grew out of the work of many scientists and improvements in the microscope. Many scientists contributed to the cell theory. The cell theory grew out of the work of many scientists and improvements in the microscope. - PowerPoint PPT Presentation

Transcript of KEY CONCEPT Cells are the Basic unit of life.

3.1 Cell Theory

MAIN IDEA

Cells are the basic “building blocks” of all living things.

3.1 Cell Theory

The cell theory grew out of the work of many scientists and improvements in the microscope.• Many scientists and nonscientists, over hundreds of years

have contributed to our present day understanding of cell structure and function.

3.1 Cell Theory

The invention of the microscope in the 1600’s provided the opportunity to make detailed observations of cell structures and activities.

3.1 Cell Theory

Robert Hooke 1665

Observed holes in cork under microsocope.

Coined the term “cells”

Empty spaces were actually where living cells were before dying – he just saw cell walls

3.1 Cell Theory

Anton von Leeuwonhoek (just call me Tony)

* Dutch lens maker

* First to observe and describe

single-celled microorganisms

Ex. bacteria and protists

* Called them animalcules and

cavorting beasties 

3.1 Cell Theory

Robert Brown

Robby Bobby said –

“That dark structure found inside many cells should be named the Nucleus”

3.1 Cell Theory

Theodore Schleiden

Ted said -

“All plants are made of cells”

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Matthias Schwann

Matt knew where it was at when he declared

“ALL animals (like swans) are made of cells”

3.1 Cell Theory

Rudolf Virchow

Rejected the concept of spontaneous generation, which held that organisms could arise from nonliving matter spontaneously.

Rudy’s Rule:

“All cells are made by other cells”

3.1 Cell Theory

Theory –

An explanation for a wide body of evidence gathered over time through observation and experimentation.

A theory ties lots of findings together and tries to provide a unifying explanation.

3.1 Cell Theory

The cell theory grew out of the work of many scientists and improvements in the microscope.• Many scientists contributed to the cell theory.• More was learned about cells

as microscopes improved.• The cell theory is a unifying

concept of biology.

3.1 Cell Theory

3 Principles of the Cell Theory

1. All organisms are made of cells.

3.1 Cell Theory

3 Principles of the Cell Theory

1. All organisms are made of cells.

2. All cells are made by other living cells

3.1 Cell Theory

3 Principles of the Cell Theory

1. All organisms are made of cells.

2. All cells are made by other living cells

3. Cells are the “building blocks” of all life

.

3.1 Cell Theory

There are thousands of different types of cells that make up living organisms.

3.1 Cell Theory

Two categories of cells based on their internal structure.

1. Prokaryotic Cells

DO NOT have a nucleus or organelles surrounded by membranes

2. Eukaryotic Cells

DO have a nucleus and membrane surrounded organelles

3.1 Cell Theory

Two major cell types: Eukaryotic cells and Prokaryotic cells

Eukaryotic cells have a nucleus.

nucleus

cell membrane

3.1 Cell Theory

Two major cell types: Eukaryotic cells and Prokaryotic cells

• Eukaryotic cells have a nucleus.

• Eukaryotic cells have

membrane-bound organelles.

nucleus

cell membrane

organelles

3.1 Cell Theory

Two major cell types: Eukaryotic cells and Prokaryotic cells

•Prokaryotic cells do not

have a nucleus.

nucleus

cell membrane

organelles

3.1 Cell Theory

Two major cell types: Eukaryotic cells and Prokaryotic cells

• Prokaryotic cells do not have a nucleus.

• Prokaryotic cells do not have membrane-bound organelles.

nucleus

cell membrane

organelles

cytoplasm

3.1 Cell Theory

Fossil Evidence of Prokaryotic and Eukaryotic Cells

PROKARYOTES

Photosynthetic marine bacteria

3.5 Billion Years Ago

EUKARYOTES

Evolved 1.5 billion yrs ago

First ones were unicellular

Later cells became multicellular

3.1 Cell Theory

Organisms are made of either prokaryotic or eukaryotic cells

Prokaryotes are organisms made of Prokaryotic cells

Only Bacteria are Prokaryotes

Eukaryotes are organisms made of Eukaryotic cells

Organisms include:•Protists•Fungi•Plants•Animals

3.1 Cell Theory

Cells come in many different shapes and carry out many different jobs. However they all share some features.

All cells do share some characteristics•Most cells are microscopic.

Bacterium(colored SEM; magnification 8800x)

3.1 Cell Theory

All cells share some characteristics•Most cells are microscopic•All cells are separated from their environment by a plasma membrane

Bacterium(colored SEM; magnification 8800x)

cell membrane

3.1 Cell Theory

All cells share some characteristics•Most cells are microscopic•All cells are enclosed by a plasma membrane•All cells are filled with gel like fluid called cytoplasm

Bacterium(colored SEM; magnification 8800x)

cell membrane

cytoplasm

3.1 Cell Theory

All cells share some characteristics•Most cells are microscopic•All cells are enclosed by a plasma membrane•All cells are filled with cytoplasm•All cells contain DNA

Bacterium(colored SEM; magnification 8800x)

cell membrane

cytoplasm

3.1 Cell Theory

3.1 Cell Theory

Endosymbiotic Theory• Developed in the 1970’s

• Endosymbiosis- a relationship in which one organism lives within the body of another and both benefit from relationship.

• Early mitochondria and chloroplasts were once simple prokaryotic cells that were taken up by larger prokaryotes around 1.5 bya. Some of the smaller prokaryotes may have survived inside the larger ones. Survival advantage-Both structures helped the larger cell get energy.

Mitochondria and Chloroplasts have their own DNA & ribosomes, can copy themselves

3.1 Cell Theory

Endosymbiosis

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Helpful Animations and Videos

Prokaryotic vs. Eukaryotic Cells: Comparison and Contrast

http://science.howstuffworks.com/life/28732-assignment-discovery-elements-of-cells-video.htm

http://www.youtube.com/watch?v=y623clAREHI

http://www.youtube.com/watch?v=yWy4o_UfZ4A

http://www.youtube.com/watch?v=WRO-DPyB9Bk

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Parts of a Prokaryotic Cell

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Prokaryotic Cells

No Nucleus

No membrane surrounded organelles

Smaller

Single celled/ Unicellular

Found in bacteria, archaea

Circular DNA

Ribosomes – not surrounded by a membrane

Eukaryotic CellsNucleus

Membrane surrounded organelles

Larger

Single or Multicellular

Found in protists, fungi, plant and animals

Linear DNA

Ribosomes (protein factories)

3.1 Cell Theory