science 7 – lt unit 3 - classification and introduce microscopes

Science 7 – LT Unit 3 Science 7 – LT Unit 3 - Classification and - Classification and Introduce Introduce MicroscopesMicroscopes

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What do we know now?What do we know now?

What have we been learning?What have we been learning?

Big Picture – Where we Big Picture – Where we are headingare heading

Learn how to:Learn how to: Classify OrganismsClassify Organisms Use MicroscopesUse Microscopes

Bring it together using critters and water Bring it together using critters and water samples from our classroom pondsamples from our classroom pond

ClassificationClassification

A system to A system to sort outsort out organisms based on organisms based on their propertiestheir properties

Scientific name is called TAXONOMY Scientific name is called TAXONOMY (based on Greek word taxa = “to sort”)(based on Greek word taxa = “to sort”)

Observations used to determine Observations used to determine similarities and differences in organismssimilarities and differences in organisms

Kingdom

Phylum

Class

Order

Family

Genus

Species

Kingdom – “King”

Phylum- “Phillip”

Class – “Came”

Order – “Over”

Family – “For”

Genus – “Great”

Species – Spaghetti

Current System Used for Current System Used for Living ThingsLiving Things

Carl Linnaeus 1700’sCarl Linnaeus 1700’s The species name is The species name is

sometimes called a sometimes called a binomial (a two-term binomial (a two-term name). For example, the name). For example, the zoological name for the zoological name for the humanhuman species is species is Homo Homo sapienssapiens: :

In this case, In this case, HomoHomo is the is the generic name and refers to generic name and refers to the genus; it is capitalized; the genus; it is capitalized; sapienssapiens indicates the indicates the species: it is written in species: it is written in lower case.lower case.

KeysKeys

Branching KeyBranching Key Dichotomous KeyDichotomous Key

Branching KeyBranching Key Asks Yes or no Asks Yes or no

QuestionsQuestions ““Branches” Branches”

outward from outward from main question main question

Ends when a Ends when a unique answer unique answer is in place for is in place for all itemsall items

DichotomoDichotomous Keyus Key ““Di” – means 2 Di” – means 2

“It is either this “It is either this or that”or that”

Look at first Look at first itemitem

Ask Question Ask Question #1 – move on #1 – move on to question it to question it directs you todirects you to

Learning how to use the microscopeLearning how to use the microscope

There are 2 kinds of microscopes:There are 2 kinds of microscopes:

Simple: Simple: one lensone lens ( (magnifyingmagnifying glass) glass)

Compound: Compound: 2 or more lenses2 or more lenses Monocular – 1 eyepieceMonocular – 1 eyepiece Binocular – 2 eyepiecesBinocular – 2 eyepieces

Parts of the MicroscopeParts of the Microscope

1.1.Revolving Revolving NosepieceNosepiece

Holds the hHolds the highigh and land lowow power power objective objective lenseslenses; ; can be rotated can be rotated to change to change magnificationmagnification

Parts of the MicroscopeParts of the Microscope

2. 2. Objective Objective LensesLenses

Magnification Magnification ranges from ranges from 4x4x to to 40x40x

Parts of the MicroscopeParts of the Microscope

3. 3. StageStage

Supports the Supports the slideslide being being viewedviewed

Parts of the MicroscopeParts of the Microscope

4. 4. DiaphragmDiaphragm

Controls the Controls the amount of amount of lightlight on a specimenon a specimen

Parts of the MicroscopeParts of the Microscope

5. 5. Light sourceLight source

Projects light Projects light upwardsupwards through through the diaphragm, the diaphragm, the the specimenspecimen, , and the and the lenseslenses

Parts of the MicroscopeParts of the Microscope

6. 6. BaseBase

Supports the Supports the microscopemicroscope

Parts of the MicroscopeParts of the Microscope

7. 7. Eyepiece Eyepiece lenslens

First lens you First lens you look through.look through.

10 x 10 x magnificationmagnification

Parts of the MicroscopeParts of the Microscope

8. 8. ArmArm

Used to Used to support support the the microscope microscope when carriedwhen carried

Parts of the MicroscopeParts of the Microscope

9. 9. Stage ClipsStage Clips

HoldHold the slide in the slide in placeplace

Parts of the MicroscopeParts of the Microscope

10. 10. CourseCourse

Adjustment Adjustment KnobKnob

Moves the Moves the stagestage up and up and down for down for focusingfocusing

Parts of the MicroscopeParts of the Microscope

11. 11. FineFine

Adjustment Adjustment KnobKnob

Moves the Moves the stage slightly to stage slightly to sharpensharpen the the imageimage

Calculating MagnificationCalculating Magnification

MultiplyMultiply lens powers together! lens powers together!

What’s my power?

What are the powers of magnification for each of the objectives (letter C) we have on our microscopes?

Eyepiece: Eyepiece: 10 X 10 X by itselfby itself Low Power: Low Power: 44XX Eyepiece x Lens = Total PowerEyepiece x Lens = Total Power

Power = 10 x 4 = 40Power = 10 x 4 = 40 mainly used for mainly used for large objects/scanninglarge objects/scanning

Medium Power: Medium Power: 1010 X X Eyepiece x Lens = Total PowerEyepiece x Lens = Total Power Power = 10 x 10 = 100Power = 10 x 10 = 100

High Power: High Power: 4040 X X Eyepiece x Lens = Total PowerEyepiece x Lens = Total Power Power = 10 x 40 = 400Power = 10 x 40 = 400 mainly used for smaller objects/detailsmainly used for smaller objects/details

Safety InstructionsSafety Instructions

Make sure it is on Make sure it is on LOWLOW power to start with! power to start with! (smallest (smallest objective) objective)

The stage should be all The stage should be all the way the way downdown (you focus (you focus by slowly moving it up!)by slowly moving it up!)

Don’t touch the lens of the Don’t touch the lens of the microscope with your hands!microscope with your hands!

Carrying the Microscope: Carrying the Microscope:

Always hold in an Always hold in an uprightupright position position

Always Always use 2 use 2 hands!hands!

One holds the arm One holds the arm and the other and the other supports the base.supports the base.

Never carry by the Never carry by the eyepieceeyepiece

Other Things to Consider:Other Things to Consider:

Never use the COURSE Never use the COURSE FOCUS KNOB while on FOCUS KNOB while on HIGHHIGH power. power.

Why? Why? You could break the You could break the lens! lens! $$$$$$$$$$$$

only use the fine adjustment on high only use the fine adjustment on high powerpower

TROUBLESHOOTINGTROUBLESHOOTINGWhat if you can’t get your object into What if you can’t get your object into focus?focus?

Check that you have one of Check that you have one of the lenses clicked into placethe lenses clicked into place

Check that your disc Check that your disc diaphragm is in place (not diaphragm is in place (not IN IN BETWEENBETWEEN settings) settings)

TROUBLESHOOTINGTROUBLESHOOTINGWhat if you can’t get your object into What if you can’t get your object into focus?focus?

Clean off your lenses using Clean off your lenses using LENS PAPERLENS PAPER. (. (Not Kleenex tissue)Not Kleenex tissue)

GO BACK TO LOW POWER AND GO BACK TO LOW POWER AND START OVER!START OVER!

Making a Wet MountMaking a Wet Mount

Put a drop or two of the liquid you are Put a drop or two of the liquid you are studying on the slide.studying on the slide.

Place a coverslip on one edge of the drop.Place a coverslip on one edge of the drop. Slowly lower the coverslip onto the drop so Slowly lower the coverslip onto the drop so

that no air bubbles get trapped under the that no air bubbles get trapped under the coverslip.coverslip.

Looks like a cool specimen …but it’s not.

When putting the microscope When putting the microscope away (at the end of the class):away (at the end of the class):It should be on It should be on LOWLOW power. power.The cord should be The cord should be WRAPPEDWRAPPED

around the arm.around the arm.The stage should be all the way The stage should be all the way

DOWNDOWN (do this with the course (do this with the course focus knob!)focus knob!)

Put the dust Put the dust covercover back on back on Put carefully back on cartPut carefully back on cart Check microscope into the teacherCheck microscope into the teacher

Let’s Try it out!Let’s Try it out!In Journal: title In Journal: title “Microscope Drawing ”“Microscope Drawing ”

Draw what you see after focusing the Draw what you see after focusing the imageimage

Label the image (what is it called)Label the image (what is it called) Label magnification (power) on drawingLabel magnification (power) on drawing

For example:

Onion cell

Power = 10 x 40 = 400

Group roles:Group roles:

1.1. CarefullyCarefully go get a microscope go get a microscope

2.2. Get a slide on back tableGet a slide on back table

3.3. Clear off desks completelyClear off desks completely

4.4. Clean up dutyClean up duty

Must pass microscope quiz Must pass microscope quiz before you can do the Pond before you can do the Pond Lab.Lab.