Microscope Basics pages 140 - 147 Parts and focusing Cell Theory History

Microscope Basicspages 140 - 147

Parts and focusingCell Theory

History

Label the Compound Light Microscope(Handout)

Ocular lens

Body TubeCoarse Adjustment KnobFine adjustment KnobRevolving nosepieceObjective lenses (4x, 10x, 40x)ArmStage Stage ClipsDiaphramLight source

Base

http://www.google.ca/imgres?imgurl=http://www.teachnet.ie/tburke/cell/microscope.jpg&imgrefurl=http://www.teachnet.ie/tburke/cell/microscope.html&h=481&w=360&sz=78&tbnid=e9EKCZIiTgKs-M:&tbnh=260&tbnw=195&prev=/images%3Fq%3Dmicroscope%2Bpicture&usg=__0GGsnP0_ro5E6L8EHv_hUCsyxZo=&ei=otbNS4roOcTflge84J2fCw&sa=X&oi=image_result&resnum=2&ct=image&ved=0CAsQ9QEwAQ

The Eyepiece: This is the where you look into the microscope. Eyepieces are usually labeled x10 or x15.

The Objective Lens: There are usually three objective lenses. Typically these would be labeled X4, X10 and X40 on a school microscope.

The Stage: Is the part of the microscope which holds the slide.

The Slide: Is a rectangular piece of glass used to hold the specimen.

A Coverslip: Is a piece of thin glass placed over the item you are examining on the slide.

The Coarse Focus: is used to focus the microscope on the item you are examining.

The Fine Focus: is used to change the focus slightly, so that the specimen (the item under examination) is very clear.

The Light: is used to illuminate the specimen. In order to view something with a microscope. Some microscopes use a mirror instead of a light.

The magnification of a microscope: Is calculated by multiplying the eyepiece power by the objective power. Therefore if we have a X10 eyepiece and have selected a x15 objective lens the magnification is 150. This means that the object we are looking at a specimen being magnified 150 times.

Focusing with a Microscope1. Plug in and turn on.2. Lower stage completely.3. Turn nosepiece to low objective.4. Raise stage with coarse objective until specimen

is seen. (Big knob)5. Fine focus the specimen.6. Centre specimen in the field of view.7. Rotate nosepiece to medium power objective.8. Refocus with fine adjustment.9. Re-centre the specimen.10. Refocus with fine adjustment. (Be careful not to

break the slide.)11. Adjust the condenser. (Light)12. Start over to look at another specimen.13. Carrying and storage instructions.

Microscope and Cells

Microscope DemonstrationMicroscope Introductionhttp://www.youtube.com/watch?v=2xdMaeLJ2Mg&feature=related

Preparing a plant and animal cell slidehttp://www.youtube.com/watch?v=GHnndVuaync&feature=related

http://www.youtube.com/watch?v=2xdMaeLJ2Mg&feature=related

http://www.youtube.com/watch?v=GHnndVuaync&feature=related

Onion Cellhttp://www.youtube.com/watch?v=Tdch3mxQ4oU&feature=related

http://www.youtube.com/watch?v=Tdch3mxQ4oU&feature=related

Microscope History and Development

Field of view and Magnification

Early Microscopes - Anton Van Leeuwenhoek

The father of microscopy, Anton Van Leeuwenhoek of Holland (1632-1723).

Anton Van Leeuwenhoek was the first to see and describe bacteria (1674), yeast plants, the teeming life in a drop of water, and the circulation of blood corpuscles in capillaries.

Robert Hooke

In 1665, the English physicist Robert Hooke looked at a sliver of cork through a microscope lens and noticed some "pores" or "cells" in it.

Hooke was the first person to use the word "cell" to identify microscopic structures when he was describing cork.

http://www.arsmachina.com/hooke.htm

Antique microscopes (link)

http://www.arsmachina.com/micro_1.htm

Technological Advances in Microscopes

Compound Light Microscopes

Uses light Has two lenses Magnification limited to 2000x

(400x at GMCS)

Transmission Electron Microscope (TEM)

Uses beams of electrons Magnification of 2 000 000x Has two limitations:

Good only for thin specimens Only dead cells can be observed

Scanning Electron Microscope (SEM)

Electrons are reflected from the surface of the specimen

Produces a 3-d image Good for the thicker specimens Lacks the magnification and

resolution of the transmission electron microscope

Magnification

Magnification = Objective lens X Ocular lens

(4x, 10x, 40x)(10x)

Calculating the size of a specimen

binder

Calculating the size of a specimen

Example under med. objectiveObject size = Size of field of view

Number of objects across field of view

Object size = 1.72 mm 14

Object size = 0.1 mm

Cell Basics (3)

Microscope question sheet (HO)Do in class, distribute and go over together.

The Cell – Need to know BasicsAnimal and Plant Organelles

(colour HO)Compare Animal and Plant cells

(Venn HO)

The Cell – Need to know Basics

Cells are the “building blocks” of the human body.

Every part of your body – bones, skin, nerves, hair, and muscle – is made if cells.

Different cells do different jobs and have different shapes and sizes.

Cells contain smaller “insides” called organelles – all with different jobs.

Organelles The largest and most important organelle

is the nucleus. The nucleus controls everything that

happens inside the cell. (Like the cells brain.)

All cells are surrounded by a protective layer called the cell membrane.

The cell membrane is semi-permeable, which means that it lets some substances pass through it, but not others.

The rest of the cell is called cytoplasm. Cytoplasm is a liquid containing chemicals needed to keep the cell alive as well as hold the floating parts of the cell together.

Animal Cell and Organelles

Plant Cell and Organelles

Venn Comparison of Animal and Plant Cells

1. What are the two main types of cells?2. What is an organelle?3. What organelles are common to both types of

cells?4. What are the organelles found only in plant

cells?5. Why do you think that scientists refer to cells as

the ‘basic” unit of life?

AnimalCell

PlantCell

Organelles and their Functions

(4)Organelles and their Functions sheet

pages 142-143 (HO) – Go overHow does a cell relate to your school?

(HO)Cells – How it works – video (HO)

Organelles and their FunctionsOrganelle Function Animal, Plant,

both

Cell Membrane Protects, determines what can enter and exit the cell Both

Cytoplasm Gel-like substance holds all the organelles of the cell Both

Nucleus Controls the activity of the cell. Contains DNA Both

Vacuole Storage area in cells (water storage) Both

Endoplasmic Reticulum (ER)

Support and makes protein in the ribosomes Both

Mitochondria Uses food to produce

energy Both

Cell Wall Supports cell shape like a skeleton Plant

Chloroplasts Uses Sun energy to make food Plant

How does a cell relate to your school?

Cells – How it works (video)

Question sheet - HO Cells Vocabulary Quiz - tomorrow

Biological Drawings (5)

Cells Vocabulary Quiz Rules for Biological Diagramming (HO)

Epithelial cell exampleRubric for Biological Diagramming

Biological Drawing Lab (HO)

Rules for Biological Diagramming

1. Use unlined white paper and a sharp HB pencil.2. Leave an empty margin of about 1 cm all around your

page.3. Print your name at the top right hand corner. (Use a

ruler.)4. When drawing cells, choose only one cell and show the

edge of neighboring cells to show the connection.5. Title your drawing. (ex. Figure 1 – Epithelial Cell.)6. Draw the outline of your subject with clear and unbroken

lines. Your drawing should be about half the page. When possible, your drawing should be vertical.

7. Use lines to show the out of visible structures. Do not shade or colour your drawings in any way. Keep the objects in proportion to one another.

8. Use a ruler to draw horizontal lines from the structures to the right of the drawing to label (print). No crossing lines!

9. Measure (in cm or mm) your diagram at its longest point; show measure on the left side of the diagram.

10. At the bottom right corner, print the subject drawn, the magnification of the drawing, and the scale.

Rubric for Biological Drawings

Only pencil used 2

Leave a 1 cm margin 2

Name printed on top right 2

Ruler used for horizontal labeling 4

Labels are printed to the right 4

No shading is used 2

Stipples are used appropriately 2

Clear and unbroken lines 2

Total Mark 20

Biological Drawing Lab

The first specimen you draw will take up this entire side of paper (handout).

On the other side, divide your sheet into 4 squares each representing one biological drawing (total of 5).

Be sure to follow all the steps properly

and be NEAT!

Microscope Lab 1 (6)

Preparing a wet mount notes.Lab

Preparing a wet mount1. Obtain a slide, cover slip, and water bottle.2. Place a drop of water in the middle of slide.3. Obtain specimen.4. Place specimen in the drop of water.5. Holding the cover slip at a 45 degree angle to

the slide, drag the cover slip into the water and gently lower until cover slip covers specimen and pushes air our from the specimen.

To darken specimen:6. Obtain a bottle of iodine.7. Place a drop of iodine at the edge of the cover

slip.8. Allow for iodine to move under the cover slip.

Do MICROSCOPE LAB!

Microscope and Cell Theory Test (7)

Microscope Test Importance of Cell Division

Reproduction and Cell Division How do cells divide

Importance of Cell Division

Have you ever wiped out on your skateboard or bike?

Imagine how terrible it would be if every scratch or flaw on your skin remained.

Cells come from pre-existing cells through the process of cell division.

Functions of Cell Division

Healing and tissue repair. To increase the number of cells

(therefore increase the size of the organism).

To replace dead and worn out cells. To create life (in unicellular

organisms such as bacteria, and multicellular organisms such as humans).

Why don’t cells just expand so we can grow, rather than divide?

If the cell became too large, there would not be enough room to exchange materials through the cell membrane and the nucleus would get smushed therefore not allowing messages to be relayed efficiently.

In short, cell division allows an organism to grow, while still maintaining a cell size that keeps the organism healthy.

Cell division is one of the most studied, yet least understood areas of biology.

Reproduction and Cell DivisionOrganisms of all species reproduce.

They may reproduce asexually or sexually.

In asexual reproduction a single organism gives rise to offspring with identical genetic information. Ex. the cells of the human body, other than those found in the male testes and female ovaries and bacteria use asexual reproduction to produce offspring by the process of mitosis.

Daughter(46)

Daughter(46)

Mother(46)

Mitosis

In sexual reproduction, genetic

information from two cells is combined to produce a new genetically unique organism. Usually, sexual reproduction occurs when two specialized sex cells unite to form a fertilized egg called a zygote.

Egg cell(23)

Zygote(46)

Sperm Cell(23)

Sex Cells

Reproduction and Cell Division

(8)Cells Vocabulary Quiz

Rules for Biological Diagramming (HO)Epithelial cell example

Rubric for Biological Diagramming Biological Drawing Lab (HO)

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Microscope Basics pages 140 - 147 Parts and focusing Cell Theory History