What do you think these
are?
Mosquito larva
Human Flea
Your tongue
HOW DO WE USE A MICROSCOPE?
SUCCESS CRITERIA:
1. WHY do we use microscopes?
3. HOW does it work and how do I use it?
2. WHAT are the parts of a microscope?
4. CAN I calculate the magnification?
KEY WORDS:
•
•
•
•
•
•
•
•
•
•
•
Eyepiece
Focusing
Lens
Magnify
Magnification
Objective
Slide
Specimen
Stage
Stain
Turret
Your eyes are amazing
The human eye can see
detail of roughly 1mm
from up to 3m away
But they can’t see everything
MICROSCOPE
‘Micros’
small
‘Skopos’
Watcher
“A watcher of small”
Total magnification
lens and the
objective lens in a microscope
x10
The eyepiece
have different magnifications
x4
They work together to magnify the
object you are trying to see
Total Magnification = Eyepiece X Objective
What magnification is this?
x10
x20
Lily Pollen x200
RP: Preparing plant cells
c
• Make a slide using the inner
epidermis of the onion bulb by
pulling away a strip using a pair of
forceps.
1.
2.
3.
4.
5.
Cut a small piece of epidermis,
about 5 mm across
Put a drop of water on the slide and
place the tissue gently in to it on
the slide
Add a drop of dilute iodine solution
and place a cover slip on top.
Look at the slide under the
microscope, using low power to
locate the cells and then the high
power to observe detail.
Make a drawing of a small group of
cells, labelling the structures.
RP: Hopefully, you will see
Nucleus
Cell wall
Carefully draw and label the cells you can see down
your microscope. Add the total magnification.
RP: Preparing plant cells
RP: Hopefully, you will see
Nucleus
Cell
membrane
Carefully draw and label the cells you can see down
your microscope. Add the total magnification.
Rules for drawing cells
• Use a sharp pencil
• Draw a large diagram – 2 per page would be
reasonable
• Label with a ruler
• Do not add arrow heads to your labels
• Make sure the label line touches the object you
are labelling
• Add the magnification you have used (multiply
the eyepiece magnification by the objective
magnification)
Good practice
Find the mistakes, then list the rules