LO: SWBAT explain how the cell theory was developed

Do Now: What instrument was vital for scientists to discover and learn about cells? How does this instrument work?

HW: Read pages 169-172, page 172 # 1-5

What instrument was vital for scientists to discover and learn

about cells?

Light Microscope

A light microscope can magnify objectsup to 1000 times.

This instrument allows scientists to see larger parts of a cell (cell membrane, nucleus, chromosomes, etc…)

Anton van Leeuwenhoek 1600’s

Spiral Bacteria

Human Sperm

Developed simple light microscopes that allowed him to examine tiny living organisms he called “animacules”

Robert Hooke(1665)

CORK CELLSWhat is this?

First Compound Microscope

First person to use the word “cell”

Matthias Schleiden (1838)ALL PLANTS ARE MADE OF

CELLS

Theodor Schwann (1838)ALL ANIMALS ARE MADE UP OF

CELLS

Rudolf Virchow (1858)

CELLS COME FROM

PRE-EXISTING CELLS

Cell theory• All living things are made of cells

• Cells are the basic unit of structure and function (metabolism)

• New cells come from pre-existing cells

What are some problems with the Cell Theory?

• Are viruses living?

• Where did the first cell come from?

Viruses

They are not made up of cells, but are

they living?

What do you know about viruses?

•They can make you very sick

•They can be transmitted

from person to person

•There are different types

of viruses

HOW BIG IS A VIRUS?

They are microscopic and

smaller than cells!

Too small to be seen with a light microscope

How can we determine if a virus is living or non-living?

• Is it made of cells?

• Does it maintain homeostasis?

• Does it carry out metabolism?

• Does it reproduce?

Is a virus living or non living?

Introduction to Viruses Video

How are cells classified?

How do these cells compare?

SIMPLE

COM

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Cells are broken down into two main classes:

Cells

Prokaryotic Eukaryotic

Prokaryotes:

Were probably the first life forms to appear on earth 3.5 billion years ago

Harsh Early Earth

What were the conditions on Earth at this time?1)Hot2)Little Oxygen3)Abundant Lightning4) Volcanic Activity

Why do you think Prokaryotes were the first life forms on earth?

1)Simple Structures

2) Their ability to tolerate harsh environments

3) Their ability to adaptto changing

environments

What are some features of prokaryotes?

1)Prokaryotes have NO NUCLEUS!!2) Have few organelles (mini-organs)3) PROKARYOTES = BACTERIA

** Although prokaryotes do not have nuclei, theydo have DNA.

What organisms are made up of eukaryotic cells?

Plants Animals Fungi Protists

All other living things are made up of Eukaryotic Cells

What are some features of typical eukaryotic cells?

1) They are more complex

2) Appeared later on earth

3) They have nuclei4) They are larger5) Have more organelles6) Have membrane

boundorganelles

Eukaryotes

CELL TYPES

• PROKARYOTIC

• HAVE only a few ORGANELLES

• HAVE NO NUCLEUS

• PRIMITIVE CELLS

• Only Bacteria

• EUKARYOTIC

• HAVE ORGANELLES

• HAVE NUCLEUS

• MODERN CELLS

• All other living things: animals, plants, fungi, protist (unicellular organisms)

What do all cells have in common?

• Cell membrane – gives shape to the cells and allows things in and out.

• The cytoplasm – the jelly like material where all cell parts are found

Compare and contrast these two cars?

SIMPLE

COMPLEX

How Do These Cells Compare?

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COM

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Eukaryotes evolved from prokaryotes