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Review Facts Review Facts About Living About Living
ThingsThings
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What Are the Main What Are the Main Characteristics of Characteristics of
organisms?organisms?1.1. Made of Made of CELLSCELLS2.2. Require Require ENERGYENERGY (food) (food)3.3. REPRODUCEREPRODUCE (species) (species)4.4. Maintain Maintain HOMEOSTASISHOMEOSTASIS5.5. ORGANIZEDORGANIZED6.6. RESPONDRESPOND to environment to environment7.7. GROWGROW and and DEVELOPDEVELOP8.8. EXCHANGEEXCHANGE materials with materials with
surroundings (water, wastes, surroundings (water, wastes, gases)gases)
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LEVELS OF ORGANIZATIONLEVELS OF ORGANIZATION
Living Levels:Living Levels:
1.1. CELLCELL (makes up ALL organisms) (makes up ALL organisms)
2.2. TISSUETISSUE (cells working together (cells working together
3.3. ORGANORGAN (heart, brain, stomach …) (heart, brain, stomach …)
4.4. ORGAN SYSTEMSORGAN SYSTEMS (respiratory, circulatory (respiratory, circulatory
…)…)
5.5. ORGANISMORGANISM
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THE CELLTHE CELL All living things are All living things are
made of made of cells.cells.
Cells are the basic unit Cells are the basic unit of life.of life.
Cells come from the Cells come from the reproduction of existing reproduction of existing cells cells (cell division).(cell division).
The MicroscopeThe Microscope
Learning ObjectivesLearning Objectives
By the end of this topic, you will be able By the end of this topic, you will be able to:to:
1.1. Name the parts of the microscope Name the parts of the microscope and their functions.and their functions.
2.2. Use the microscope to observe Use the microscope to observe biological specimensbiological specimens
3.3. Know the difference between the Know the difference between the light microscope and the electron light microscope and the electron microscopemicroscope
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First to View CellsFirst to View Cells In 1665, In 1665, Robert Robert
HookeHooke used a used a microscope to microscope to examine a thin examine a thin slice of slice of corkcork (dead plant cell (dead plant cell walls)walls)
What he saw What he saw looked like small looked like small boxesboxes
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First to View CellsFirst to View Cells Hooke is Hooke is
responsible for responsible for naming cellsnaming cells
Hooke called Hooke called them “CELLS” them “CELLS” because they because they looked like the looked like the small rooms that small rooms that monks lived inmonks lived in called Cellscalled Cells
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Anton van Anton van LeeuwenhoekLeeuwenhoek
In 1673, In 1673, LeeuwenhoekLeeuwenhoek (a (a Dutch microscope Dutch microscope maker), was maker), was first first to view organismto view organism (living things)(living things)
Leeuwenhoek used Leeuwenhoek used a simple, handheld a simple, handheld microscope to microscope to view view pond water & pond water & scrapings from his scrapings from his teethteeth
Compound MicroscopesCompound Microscopes
a.a. The The Eyepiece LensEyepiece Lens is is the lens that you look the lens that you look through.through.b.b. The The objective lensobjective lens is the is the lens that is immediately lens that is immediately above the specimen.above the specimen.
The microscopes used in our lab are called compound microscopes because they have two magnifying lens
The Objective LensesThe Objective LensesThere are three objective lenses:There are three objective lenses:
- the scanning lens with the 4X - the scanning lens with the 4X labellabel
- the low power lens with the 10X - the low power lens with the 10X labellabel
- the high power lens with the 40X - the high power lens with the 40X labellabel
Parts of the MicroscopeParts of the Microscope
The MicroscopeThe MicroscopeEyepiece
Nosepiece
Objective Lens
Stage
Clips
Light
Diaphragm
Course Focus
Fine Focus
Parts of the MicroscopeParts of the MicroscopePartPart FunctionFunction
LensesLenses MagnificationMagnification
StageStage To place the slide onTo place the slide on
ClipsClips Hold the slide in placeHold the slide in place
DiaphragmDiaphragm To control the amount of To control the amount of lightlight
Coarse Focus Coarse Focus KnobKnob
To focus the imageTo focus the image
Fine Focus KnobFine Focus Knob To precisely focus the To precisely focus the imageimage
LightLight To supply light to the objectTo supply light to the object
Learning CheckLearning CheckLabel the parts of the Label the parts of the
MicroscopeMicroscope
MagnificationMagnificationMagnification = the magnifying power of the eyepiece lens
x the magnifying power of the objective lens.
Example:
Eyepiece lens = 10XObjective lens = 4X
Total magnification = 10 x 4= 40X
Focussing The ImageFocussing The Image
The course focuscourse focus knob allows for dramatic or large movement of the objective lens.
The fine focusfine focus knob allows for very slight movement of the objective lens.
2.1.1 Microscopy.exe
The Stage and the The Stage and the DiaphragmDiaphragm
The stagestage has two metal clips to hold the microscope slide in place.
The diaphragmdiaphragm allows light to be focused onto the specimen through a hole in the stage.
Light MicroscopeLight Microscope
Elodea - Aquatic Plant
40X 400X
ELECTRON MICROSCOPEELECTRON MICROSCOPE
Electron MicroscopeElectron Microscope
Uses Electrons instead of lightUses Electrons instead of light
Electrons have much lower wavelength Electrons have much lower wavelength than lightthan light
Resolution is much betterResolution is much better
Magnification is much greaterMagnification is much greater
Images from Electron Images from Electron MicroscopeMicroscope
Bacteria
Cytplasm
Platelet
Now lets get Now lets get familiar with the familiar with the
light microscope by light microscope by using it!using it!
https://www.youtube.com/https://www.youtube.com/watch?v=jP9HtcAvGDkwatch?v=jP9HtcAvGDk
How to correctly use How to correctly use microscopemicroscope
Draw labelled diagrams of your observations under low power and under high power.
Learning CheckLearning CheckWhat is the function of each of What is the function of each of these parts of the Microscope?these parts of the Microscope?
Eyepiece Lens Eyepiece Lens Objective Objective LensLens
StageStage ClipsClips
DiaphragmDiaphragm Coarse Focus Coarse Focus KnobKnob
Fine focus KnobFine focus Knob Light Light
What have you learned?What have you learned?
Can you?Can you?
1.1. Name the parts of the microscope Name the parts of the microscope and their functions.and their functions.
2.2. Use the microscope to observe Use the microscope to observe biological specimensbiological specimens
3.3. Outline the differences between Outline the differences between the light microscope and the the light microscope and the electron microscopeelectron microscope
ENDEND