The document discusses different types of microscopes, including compound light microscopes which can magnify up to 1000x and electron microscopes which use beams of electrons instead of light to examine samples at magnifications over 1000x. It describes the key parts of microscopes like the objectives, eyepiece, stage, and mechanical components used to focus and move the microscope. The document also provides information on how biologists use microscopes to study cells and small organisms.

1. The Microscope

2. What structure
in an animal’s
body is this?
Where are these found?

3. How do biologists study cells?

4. A microscope is an
instrument that
produces
magnified images
of tiny structures.

5. Early Microscope

6. Early Microscope

7. Modern Microscopes

8. Compound Light Microscope
 contains more than one lens
 magnification: up to 1000x
 useful for studying many kinds of
cells and small organisms

9. Electron Microscope
 in the 1920s, a German physicist discovered a way
to use magnets to focus beam of electrons
 uses a beam of electrons instead of light to
examine a sample
 magnification: as much as 1000x larger than a
light microscope

10. Electron Microscope
 Two Kinds:
 Transmission Electron
Microscope (TEM)
 Scanning Electron
Microscope (SEM)

11. TEM
 gives a 2 - D view
 works much like a
slide projector
 specimen must be
cut into very thin
slices so that the
electron beam can
pass through

12. SEM
 gives a 3 - D view
 uses a thin beam of
electrons to scan a
sample’s surface
 does not reveal the
internal structure of a
sample

13. Images produced by light and electron
microscope

14. Terms to remember:
Magnification – ability of the microscope to
magnify or enlarge an object (example:
5x, 10x, 45x)
Total Magnification: magnification of the
eyepiece x magnification of the objective
Resolution = sharpness of an image

15. Parts of the Microscope

16. Parts of the Microscope
Three main parts:
A. Optical Parts
B. Illuminating Parts
C. Mechanical Parts

17. A. Optical Parts
- used for magnification of
the image
1. Ocular / eyepiece
2. Objectives

18. A. Optical Parts
Objectives – tubes attached to the revolving
nosepiece
A. SPO (4x) – gives an overview of the
specimen
B. LPO (10x) – used for locating parts of the
specimen
C. HPO (40x) – use to view small details of
the specimen

19. B. Illuminating Parts
- used to focus or direct light
1. Mirror - used to reflect light
- plane, convex
2. Diaphragm - regulates the amount of
light reflected

20. C. Mechanical Parts
- necessary for movement and
support
1. Base – allows the microscope to stand
2. Pillar – supports the stage
3. Stage – where glass slide is placed
4. Arm – curved part grasped when
carrying the microscope

21. C. Mechanical Parts
5. Revolving nosepiece – where the
objectives are attached
6. Draw tube – holds the eyepiece
7. Coarse adjustment knob – raises or
lowers the body tube to bring image into
focus
8. Fine adjustment knob – focuses image
further

22. C. Mechanical Parts
9. Inclination joint – allows tilting of the
microscope
10. Mirror rack – holds mirror in place
11. Stage clip – holds specimen in place
on the stage