Introduction to Cells

What are Cells?How Were They Discovered?

Cells

• What is this:

• What is this:

--

- -

Robert _________ (1665)• An English scientist who observed

cork under the microscope. He thought each circle looked like a monk’s cell.

• Hooke named These structures “___________”

Antoni van Leeuwenhoek saw wiggling, swimming “ ______________”

(200 x)

What Were They?• Leeuwenhoek was the first person to

see _______________________________ (_____________________)

• Before him, people had no idea that there were _______ _______ they couldn’t see!

• People started to realize that there were more “__________” living things than ____________ on the planet.

• _____________________ (1858) – observed living cells under a microscope for _____ periods of time. He figured out that:

____________________________________________________(there is no such thing as “____________ ____________…”)

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

Cell Theory(Mid-1800’s)

• Many years after Hooke discovered cells, a ________ of all living things was derived...

–1.) All _________ are made of _______ (cells are the _____ ______ of ______).

–2.) Cells are the ________ and ____________ units for organs, and organisms. Cells work _________ to make living things __________.

–3.) All____ come from _________ ____.

ALL cells have 3 main parts

Cell Membrane: _______ _______Regulates what _______ / _________

Genetic material: _________ _______l

Cytoplasm: ______ between cell membrane and genetic material

How Small are Cells?

• Most cells are ____________:

• They cannot be ______ with the _______ _____

Harvard Cell Video: http://www.studiodaily.com/main/technique/tprojects/6850.html

Text

Microscopes…what do they do to cells?

• ______________– _______

• ______________– ________

Type 1: Light Microscope

Light Microscope

• Shines normal _____ _______ a specimen to observe its ________

• Advantage:– ___________– Easy to __________

• Disadvantages:– Must _____ cells for resolution– Max magnification ______X

Type 2: Phase Microscope

Phase Microscope• Advantage:

– Easy to __________– Multiple _________ allow for looking at

_______ specimens with ________ resolution• Disadvantages:

– More __________ than a regular light microscope

– Max magnification ________X

Type 3: Transmission Electron Microscope (TEM)

Transmission Electron Microscope• Uses _________ to see the

__________ of cells• Advantage:

– High __________________ (__________X-___________X)

– Fine resolution _________ cells• Disadvantage:

– Very __________ to purchase and operate

– Specimens must be ________ with _________ (eg. _______)

Type 4: Scanning Electron Microscope (SEM)

Scanning Electron Microscope

• Advantages & Disadvantages:– Same as ______ – Coats the specimen with _____

and scans the _______ of a cell.

Scanning Electron Microscope

• Advantages & Disadvantages:– Looks at ____________ (__________ _______

off instead of ____________)

Fluorescent dyes

• Fluorescent dyes can be used to look at cells.

• What type of microscope do you think can be altered to use fluorescence?

Types of Cells• Scientists have discovered that all

_____ on earth can be divided into _____ basic _______:

_________ and _________

Prokaryotes• They are ______ _________ –

not much inside: ___ ___________ or ____________-

________ __________________

The only structures inside a prokaryote are ______________ and ________ _____ (______________________)

Bacteria = Prokaryotes

• Bacteria ________________________________. They can live today in many habitats: with/ without ________, ______ hot ______, extremely _______ and __________________ environments

Eukaryotes• “________” Cells –

contain a _______________ ________and many different types of _____________.

• ______ living things on earth are eukaryotes.

Some Eukaryotes are Unicellular

• These are called __________________ (Kingdom _________)

• Examples: ________, ___________, __________

Paramecium: http://www.youtube.com/watch?v=fmwN_mD7TvY

Amoeba:http://www.youtube.com/watch?v=gKNzzxuz6uk

________ Eukaryotes are _____________________!

There are Two Types of Eukaryotic Cells

• _____ _____–Have ___ _____,

_________, & central ________

• _________ ______–Do not have a ____

___ or _________. They grow in many _______!

There are Two Types of Eukaryotic Cells

Prokaryotic vs. Eukaryotic

• _____________• _______ in size• Has a ________ __________ and __________• No membrane-

bound __________

•______________•________ in size•Has a ________ _________, only plant cells have a ___________•Contain ____________________________

Are the following images prokaryotic or eukaryotic cells?

Why??

Cell membrane

Nucleus (contains DNA)

Cytoplasm

• What kinds of eukaryotic cells are these?

What kinds of eukaryotic cells do the following images show?

Summarize:• 1.) How were cells discovered?• 2.) What is the cell theory?• 3.) How can we see cells?• 4.) What are the two main types of cells?• 5.) What are the two types of eukaryotic

cells?• 6.) Are you made of cells? Guess how

many!

Assignment• Make a Venn diagram to compare/ contrast

prokaryotic and eukaryotic cells

• Include the following words: cell membrane cytoplasmnucleus genetic materialsmaller largerplant animal bacteriamembrane-bound organelles

Cell Theory (Once Again...)• Extra Credit Homework

–Find out who Lynn Margulisis.• Why is she famous in the nerdy world of biology?

• What did she discover or propose (what did she think of)?