Download Cells and Microscopy

Cells and Microscopy
The Big Questions
• How do we even know cells are even
there?
• What has advanced our understanding
of cells?
Specification Link
• Describe how plant and animal cells can
be studied in greater detail with a light
microscope
• Demonstrate an understanding of how
changes in microscope technology have
enabled us to see cells with more clarity
and detail than in the past, including
simple magnification calculations
Light Microscopes
• Microscopes let us see things that we
can’t see with the naked eye.
• Light microscopes were invented in the
1950’s. They let us see things like
nuclei, chloroplasts and mitochondria.
PARTS OF A
MICROSCOPE
Eyepiece
Lens
Handle
Objective
Lens
Focusing
Knob
Stage
Mirror
Test
Microscopes
Light Microscopes
• Invented in
1590’s.
• They let use see
things like nuclei,
chloroplasts and
mitochondria.
Electron Microscopes
• Invented in the
1930’s.
• Let use see much
smaller things in
more detail like
the internal
structure of
mitochondria and
chloroplasts.
Magnification
• The length of
the magnified object = Length of the object X Magnification
• Rearranging this tells us that
Length of object
=
Length of the magnified object
The magnification
You need to learn
those equations!!
1. A scientist looks at a cell with a microscope that has
a magnification of times 40.
The cell is 0.1 mm long.
Calculate the size of the magnified image.
(2)
2. The electron microscope can magnify
images...........................................................................than
the light microscope.
(ii) The diagram shows a sperm cell that has been
magnified 100 000 times.
Calculate the actual length of the sperm cell.