Microscope Basics
pages 140 - 147
Parts and focusing
Cell Theory
History
Label the Compound Light Microscope
(Handout)
Ocular lens
Body Tube
Coarse Adjustment Knob
Fine adjustment Knob
Revolving nosepiece
Objective lenses (4x, 10x, 40x)
Arm
Stage
Stage Clips
Diaphram
Light 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=e9EKCZIiTgKsM:&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 Microscope
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Plug in and turn on.
Lower stage completely.
Turn nosepiece to low objective.
Raise stage with coarse objective until specimen is
seen. (Big knob)
Fine focus the specimen.
Centre specimen in the field of view.
Rotate nosepiece to medium power objective.
Refocus with fine adjustment.
Re-centre the specimen.
Refocus with fine adjustment. (Be careful not to
break the slide.)
Adjust the condenser. (Light)
Start over to look at another specimen.
Carrying and storage instructions.
Microscope and Cells
Microscope Demonstration
Microscope Introduction
http://www.youtube.com/watch?v=2xdMaeLJ2Mg&feature=related
Preparing a plant and animal cell slide
http://www.youtube.com/watch?v=GHnndVuaync&feature=related
Onion Cell
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.
Antique microscopes (link)
Technological Advances in
Microscopes
Compound Light Microscopes
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

Uses light
Has two lenses
Magnification limited to 2000x (400x at
LHHS)
Transmission Electron Microscope
(TEM)
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
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)
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
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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. objective
Object 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
Do
question sheet (HO)
in class, distribute and go over together.
The
Cell – Need to know Basics
Animal and Plant Organelles
Compare
(colour
HO)
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
Animal
Cell
1.
2.
3.
4.
5.
Plant
Cell
What are the two main types of cells?
What is an organelle?
What organelles are common to both types of cells?
What are the organelles found only in plant cells?
Why do you think that scientists refer to cells as
the ‘basic” unit of life?
Organelles and their Functions
(4)
Organelles
and their Functions sheet
pages 142-143 (HO) – Go over
How does a cell relate to your school?
(HO)
Cells – How it works – video (HO)
Organelles and their Functions
Organelle
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)
Rubric
Epithelial
cell example
for Biological Diagramming
Biological Drawing Lab (HO)
Rules for Biological Diagramming
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Use unlined white paper and a sharp HB pencil.
Leave an empty margin of about 1 cm all around your page.
Print your name at the top right hand corner. (Use a ruler.)
When drawing cells, choose only one cell and show the edge of
neighboring cells to show the connection.
Title your drawing. (ex. Figure 1 – Epithelial Cell.)
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.
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.
Use a ruler to draw horizontal lines from the structures to
the right of the drawing to label (print). No crossing lines!
Measure (in cm or mm) your diagram at its longest point; show
measure on the left side of the diagram.
At the bottom right corner, print the subject drawn, the
magnification of the drawing, and the scale.
Rubric for Biological Drawings
Only pencil used
Leave a 1 cm margin
Name printed on top right
Ruler used for horizontal labeling
Labels are printed to the right
No shading is used
Stipples are used appropriately
Clear and unbroken lines
Total Mark
2
2
2
4
4
2
2
2
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 mount
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:
1.
Obtain a bottle of iodine.
2.
Place a drop of iodine at the edge of the cover slip.
3.
Allow for iodine to move under the cover slip.
Do MICROSCOPE LAB!
1.
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
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


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 Division
Organisms 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.
Mother
(46)
Daughter
(46)
Mitosis
Daughter
(46)

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)
Sex Cells
Sperm Cell
(23)
Zygote
(46)
Reproduction and Cell Division
(8)
Cells
Vocabulary Quiz
Rules for Biological Diagramming (HO)
Rubric
Epithelial
cell example
for Biological Diagramming
Biological Drawing Lab (HO)
(9)
Cells
Vocabulary Quiz
Rules for Biological Diagramming (HO)
Rubric
Epithelial
cell example
for Biological Diagramming
Biological Drawing Lab (HO)
(10)
Cells
Vocabulary Quiz
Rules for Biological Diagramming (HO)
Rubric
Epithelial
cell example
for Biological Diagramming
Biological Drawing Lab (HO)
(11)
Cells
Vocabulary Quiz
Rules for Biological Diagramming (HO)
Rubric
Epithelial
cell example
for Biological Diagramming
Biological Drawing Lab (HO)
(12)
Cells
Vocabulary Quiz
Rules for Biological Diagramming (HO)
Rubric
Epithelial
cell example
for Biological Diagramming
Biological Drawing Lab (HO)