DO NOW:Explain this cartoon in yourown words

Microscopy is the art of Microscopy is the art of producing images for producing images for

microscopic thingsmicroscopic things that are not visible to thethat are not visible to the

human eyehuman eye..

Microscopes

Robert Hooke's microscope (1665)

The first useful microscope

was developed in the Netherlands in

the early 1600s

1. Compound Light Microscope

• Models found in most schools, uses compound lenses and light to magnify objects. The lenses bend or refract the light, which makes the object beneath them appear closer.

2. Stereoscope – this microscope

allows for binocular (two eyes) viewing of

larger specimens.

Parasite that causes disease in your liver!

Polychaete worm (aquatic)

3. Scanning Electron Microscope –

allow scientists to view a universe too

small to be seen with a light

microscope. SEMs do not use light waves; they use electrons

4. Transmission Electron Microscope

also uses electrons, but

instead of scanning the

surface (as with SEM's) electrons

are passed through very thin

specimens.

Due to the powerful laser beam, anything living would die!

A mosquito An ant

Threaded needle Scales of a moth wing

Stinger of a mosquito

DO NOW:Hand-out

Parts of a Parts of a Compound Compound

light light microscopemicroscope

The structure of a cell nucleus The structure of a cell nucleus would be seen in the greatest would be seen in the greatest

detail by use ofdetail by use of1.1. a compound light microscope a compound light microscope

2.2. an ultracentrifuge an ultracentrifuge

3.3. a dissecting microscope a dissecting microscope

4.4. an electron microscopean electron microscope

Which is the correct sequence of historical Which is the correct sequence of historical developments leading to our present developments leading to our present

knowledge of cells?knowledge of cells?

1.1. electron microscope – cell theory – compound electron microscope – cell theory – compound light microscope light microscope

2.2. compound light microscope – cell theory – compound light microscope – cell theory – electron microscope electron microscope

3.3. cell theory – electron microscope – compound cell theory – electron microscope – compound light microscope light microscope

4.4. electron microscope – compound light electron microscope – compound light microscope – cell theorymicroscope – cell theory

Bodytube

nosepiece

Objective lens

Objective lens

Stage clips

Diaphragm

Objective lens

Light source

Eyepiece/ocular

arm

stage

Coarse adj.knob

Fine adj. knob

base

Eyepiece (Ocular lens):Eyepiece (Ocular lens): magnifies the image 10xmagnifies the image 10x

&& Objectives Objectives (4x, 10x & 40x (4x, 10x & 40x magnification)magnification)

Stage ClipsStage Clips

Attached to the nosepiece

Usually three magnifications

Examples: 4X, 10X, 40X

Referred to as low and high powers

Objective lens

Low power objectiveLow power objective == used to locate the specimen on used to locate the specimen on

the slidethe slideLarger field of view (See more Larger field of view (See more

of the slide, but less details)of the slide, but less details)

High power objectiveHigh power objective = = More magnificationMore magnificationSmaller field of view but more Smaller field of view but more

detailsdetails

Deer Tick 41X Magnification

Deer Tick 164X Magnification

Deer Tick 657X Magnification

Used to adjust the amount of light entering the scope

Located beneath the stage

Coarse (big) and Fine (small) Coarse (big) and Fine (small) adjustment knobsadjustment knobs

ARMARM

Remember!!Remember!!

ALWAYS USE TWO HANDS ALWAYS USE TWO HANDS

TO CARRY THE TO CARRY THE MICROSCOPE!!!MICROSCOPE!!!

1.) 1.) Diaphragm

2.2.

3.3.

44..

55..

5.5.

Which structure is best Which structure is best observed using a compound observed using a compound

light microscope?light microscope?

1.1. a cell a cell

2.2. a virus a virus

3.3. a DNA sequence a DNA sequence

4.4. the inner surface of a the inner surface of a mitochondrionmitochondrion

After switching from the high-After switching from the high-power to the low-power power to the low-power

objective lens of a compound objective lens of a compound light microscope, the area of light microscope, the area of

the low-power field will appearthe low-power field will appear1.1. larger and brighter larger and brighter

2.2. smaller and brighter smaller and brighter

3.3. larger and darker larger and darker

4.4. smaller and darkersmaller and darker

•Is numeric value that quantifies how much a specimen has been magnified.

•Is calculated by multiplying the eyepiece power (usually 10x) by the objective lens in place.

What is the What is the lowest lowest possible possible magnification that can be magnification that can be

obtained using the microscope obtained using the microscope shown?shown?

1.1. 20x 20x

2.2. 200x 200x

3.3. 40x 40x

4.4. 800x800x

Total magnification:Total magnification:

Ocular Ocular X X ObjectiveObjective = total = total

(eyepiece) (eyepiece) magnificationmagnification

Ex.)Ex.)

Objective Objective

lenslensTotal Total

magnificationmagnification

4x4x

10x10x

43x43x

When viewed with a compound light When viewed with a compound light microscope under low power, the letter microscope under low power, the letter

"p" will appear as"p" will appear as

1.1. q q

2.2. p p

3.3. d d

4.4. bb

How have microscopes How have microscopes impacted science?impacted science?

THE ENDTHE END