Free Powerpoint Presentations

Cell theory
Page
1

DOWNLOAD

PREVIEW

WATCH ALL SLIDES

Slide 1

LESSON 3

LESSON 3

Ch. 2 Cells Section 2: Viewing Cells

Slide 2

Early Microscopes

Early Microscopes

Zacharias Janssen - made 1st compound microscope

a Dutch maker of reading glasses (late 1500s)

Slide 3

Leeuwenhoek

Leeuwenhoek

made a simple microscope (mid 1600s)

magnified 270X

Early microscope lenses made images larger but the image was not clear

Slide 4

Leeuwenhoek's microscope

Leeuwenhoek's microscope

A) a screw for adjusting the height of the object being examined

B) a metal plate serving as the body

C) a skewer to impale the object and rotate it

D) the lens itself, which was spherical

Slide 5

Modern Microscopes

Modern Microscopes

A microscope is simple or compound depending on how many lenses it contains

A lens makes an enlarged image & directs light towards you eye

Slide 6

A simple microscope has one lens

A simple microscope has one lens

Similar to a magnifying glass

Magnification is the change in apparent size produced by a microscope

Slide 7

Compound Microscope

Compound Microscope

A compound microscope has multiple lenses

(eyepiece & objective lenses)

Slide 8

Stereomicroscope

Stereomicroscope

creates a 3D image

Slide 9

Total Magnification

Total Magnification

Powers of the eyepiece (10X) multiplied by objective lenses determine total magnification.

Slide 10

Electron Microscopes

Electron Microscopes

More powerful; some can magnify up to 1,000,000X

Use a magnetic field in a vacuum to bend beams of electrons

Images must be photographed or produced electronically

Slide 11

Scanning Electron Microscope (SEM)

Scanning Electron Microscope (SEM)

Electron microscope image of a spider

produces realistic 3D image

only the surface of specimen can be observed

Electron microscope image of a fly foot

Slide 12

Transmission Electron Microscope (TEM)

Transmission Electron Microscope (TEM)

produces 2D image of thinly sliced specimen

detailed cell parts (only inside a cell) can be observed

Slide 13

Go to page:
 1  2 

Contents

Last added presentations

2010-2018 powerpoint presentations