Essential Question #2:
What types of tools are
used to address questions
about the natural world?
Textbook References: Unit 1
Miller & Levine: Ch. 1-The Science of Biology
1.1 What is Science (Pgs. 4-9)
1.2 Science in Context (Pgs. 10-16)
Campbell: Ch. 1- Biology: Exploring Life
1.7 & 1.8 The Process of Science (Pgs. 9-10)
1.9 Biology and Everyday Life (Pg. 12)
SAFETY
FIRST!
Ruler
Tape measure
Meter stick
A Typical Metric Ruler
- shows distance in centimeters.
- the other side of the ruler shows inches.
1 inch = 2.54 cm
cm
inches
According to the ruler:
How many mm are in 1 cm? _______
2 inches can be converted into ______ cm.
Triple Beam Balance
Digital Scale
Beaker
Flask
Graduated Cylinder
The Metric System
– It is used by scientists when collecting data.
– It is a universal system of measurement.
– It consists of standard base units.
– Other units are obtained by multiplying and dividing
by powers of 10, or simply moving the decimal.
-Metric SystemBase Units
Measurement
Base Unit
•
•
•
•
•
Meter
Gram
Liter
Second
Celsius
Length
Mass
Volume
Time
Temperature
Unit Conversions
Unit Conversions
• To convert length from a
large unit into a small unit,
multiply by the relevant
power of 10.
• OR simply move the
decimal to the right.
• To convert length from a
small unit into a large unit,
divide by the relevant
power of 10.
• OR simply move the
decimal to the left
Practice
CIRCLE ONE

1 m = ____________ mm
Length
Volume
Mass

25g = ____________ kg
Length
Volume
Mass

400 ml = __________ L
Length
Volume
Mass

12 cm = ____________ m
Length
Volume
Mass
Make up your own problem in the space below.
Ask your neighbor to try and solve it.
_________________________________________________
Microscopy
Essential Question #2:
What types of tools are used to address
questions about the natural world?
Today we will describe how the different types of
microscopes are used and how they have
impacted the study of biology.
MicroAngela is a creation of Tina (Weatherby) Carvalho of the Biological Electron Microscope
Facility, (BEMF), part of the Pacific Biomedical Research Center at the University of Hawaii at
Manoa.
http://www5.pbrc.hawaii.edu/microangela/methods.htm
Types of Microscopes
• Light Microscope
– the models found in most schools
– use compound lenses and light to magnify objects.
– The lenses bend or refract the light, which makes
the object beneath them appear closer.
Stereoscope
• this microscope allows for binocular viewing
of larger specimens. (Binocular means 2 eyes)
Scanning Electron Microscope (SEMs)
- allow scientists to view a universe
too small to be seen with a light
microscope.
- they use electrons (instead of light
waves) to magnify objects up to
two million times!!
Transmission Electron Microscope
Also uses electrons, but instead of
scanning the surface (as with SEM's)
electrons are passed through very
thin specimens.
Parts of a
Microscope
Light Microscope Magnifications
• Your microscope has three magnifications:
– Scanning
– Low
– High
• Each objective will have the magnification number
engraved on the side.
• The ocular lens (eyepiece) has a magnification of 10x
• Total magnification = ocular x objective
Calculating Total Magnification
Objective
Magnification
Ocular lens
Magnification
Total Magnification
Scanning
4x
10x
40x
Low Power
10x
10x
100x
High Power
40x
10x
400x
Power
General Procedures to Start
1. Make sure all backpacks and junk are out of the
aisles.
2. Always carry microscopes by the arm and base.
3. Set the microscope flat on your desk and not at the
edge.
4. Plug your microscope into the floor outlet under
your desk
5. Always start with the Scanning Objective and
increase magnification as needed.
Making a Wet Mount
Gather a thin slice/piece of your specimen.
 If your specimen is too thick, then the coverslip
will wobble on top of the sample like a see-saw.
 Place ONE drop of water directly over the
specimen.
 Too much water makes the the coverslip float
on top of the water so it is hard to find the
specimen through the microscope lens.
 Place the cover slip at a 45° angle with
one edge touching the water drop
and then gently let go.
Focusing Specimens
1. Always start with the scanning objective.
– Use the Coarse Knob to focus.
• The image may be small, but you won't be able to find it
on the higher powers without this first step.
– Try moving the slide around until you find
something.
SCANNING POWER
2. Now switch to Low Power.
– Use the coarse adjustment knob to bring the
specimen back into focus.
– Use the fine adjustment knob to increase the
sharpness
– Again, if you haven't focused on this level, you will
not be able to move to the next level.
LOW POWER (40X)
3. Now switch to High Power.
– Use only the fine adjustment knob.
– Do not use the coarse adjustment knob or you
may crack the slide.
HIGH POWER (100x)
Troubleshooting
Here are some common problems & solutions.
Image is too dark or light!
– Adjust the diaphragm, make sure your light is on.
There's a spot in my viewing field, even when I
move the slide the spot stays in the same place!
– Your lens is dirty.
– Use lens paper, and only lens paper to carefully clean the
objective and ocular lens.
 I can't see anything under high power!
– Remember the steps, if you can't focus on
scanning and then low power, you won't be able to
focus anything on high power.
Scanning
Low
Power
High
Power
Only half of my viewing field is lit, it looks like
there's a half-moon in there!
– You probably don't have your objective fully
clicked into place.
 I see a line going through my viewing field.
 Try twisting the eyepiece and the line should move.
 This needle is used for pointing out things to your
lab partner or teacher.
SEE I’M POINTING
OUT THE POINTER
THAT’S POINTING
OUT THE CELL!
GET IT ? 
Drawing Specimens
 Use pencil - you can erase and shade areas
 Drawings should be labeled with the specimen name
and magnification.
 All drawings should include clear and proper labels
(and be large enough to view details).
 Labels should be written on the outside of the circle.
o The circle indicates the viewing field as seen through the
eyepiece
 Specimens should be drawn to scale.
o What does drawing to scale mean?
o For instance, if your specimen takes up the whole viewing
field, make sure your drawing reflects that.
CHECKLIST:
Used Pencil
Shaded areas, colored
Name of Specimen
Total Magnification
Clear, proper labels
Lines do not crossover
Labels are outside circle
Drawn to scale
Sample Drawing
General Procedures to End
1. Do not remove slides while on High Power
Objective is in place- this will scratch the lens!
2. Wash slides in the sink and dry them, placing
them back in the slide boxes
3. Throw cover slips away.
4. Microscopes should be stored with the Scanning
Objective clicked into place.
5. Always wrap electric cords and place the cover
over the microscope before returning them to
the cabinet.
Essential Question #2:
What types of tools are used to address
questions about the natural world?
Measurement and
observation tools are used
to categorize, represent,
and interpret the natural
world.