The Microscope and Cells

Mrs. Byrne

a) I will discover and sketch cells under a microscope.

You will be like Robert Hooke today!

RIP: Robert Hooke, 1635-1703

Hooke Microscope

cork cells

Cork Cells

Quercus suber, Cork Oak

How Microscopes Work

a) Convex lenses are curved glass used in microscopes, etc.

b) Light is bent and focused in one spot.

The Parts of a Microscope

Body Tube

Nose Piece

Objective Lenses (three)

Stage Clips (two)

Diaphragm

Light Source

Ocular Lens

Arm

Stage

Coarse Adjustment

Fine Adjustment

Base

Magnification

Magnification a)  Multiply the ocular lens by the

objective lens. b)  Ocular lenses magnifies 10X.

c) Objective lenses have their magnification written on them.

Carry a Microscope Correctly

Using a Microscope a) Start/end on the lowest magnification

(shortest objective lens in red) b) Don’t use the coarse adjustment knob

on high magnification…you’ll break the slide!!!

c) Place slide on stage and lock clips. d) Adjust light source. e) Use fine adjustment to focus.

By the end of class, you will become familiar with a

microscope and observe some cell parts such as:

a)  Nuclei b)  Cytoplasm c)  Cell walls d)  Cell membranes

Observations

40X 100X

(Specimen Name) Details and labels!

Letter “e” slides

Cheek Cells

Preparing animal and plant cell slides:

Video clip: http://www.youtube.com/watch?v=GHnndVuaync

Iodine: Stain for cells

References •  http://www.cerebromente.org.br/n17/history/neurons1_i.htm •  Google Images •  http://science.howstuffworks.com/light-microscope1.htm

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Caring for a Microscope a) Clean only with a soft cloth/tissue.

b) Make sure it stays stationary on the lab desk.

Examples a) Under an objective lens of 4X: 10X multiplied by 4X = 40X (the specimen

is magnified 40 times). b) Magnification under a 10X objective

lens?