do now: explain this cartoon in your own words. microscopy is the art of producing images for...
TRANSCRIPT
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