Transcript Microscopes and cells

Important terms
• Magnification: ratio of an object’s image size to its real
size
• Resolving power: minimum distance between two
points at which they are still distinguishable as different
objects (measure of clarity)
• Working Distance: distance between specimen and
lens (higher magnification = smaller working distance)
• Field of View: area visible through the ocular
• Depth of field: amount of vertical distance that is in
focus
Important relationship
• Total magnification =
ocular
magnification X objective magnification
• As magnification increases:
Working distance decreases
Field of View gets smaller
of view decreases
Depth
Basic cell types
Eukaryotic cell: Possess
distinct organelles (Fungi,
Plants, Animals)
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Prokaryotic cell: Lack
distinct organelles
(Bacteria, Archaea)
Animal Cell
Plant Cell
Elodea leaf
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
http://youtube.com/watch?v=8edk6nGMwMs
Size of cells: Why aren’t cells bigger?
Review
Prokaryotes
Eukaryotes
•
No nucleus
•
Membrane-bound
nucleus
•
Circular DNA, not in
chromosomes
•
Linear DNA in
chromosomes
•
Unicellular
•
Unicellular or
multicellular
•
No membrane-bound
organelles
•
Membrane-bound
organelles
•
Binary fission
•
Asexual/sexual
reproduction
Domains
Symbioses: close relationships between two species.
Commensalism: Antbirds!
Mutualism: Trichonympha
Parasitism: Trypanosoma
Predation: Amoeba
Some things to check yourself on:
What do you know about protists?
What is the correct way to write a taxonomic name, using binomial
nomenclature?
Can you explain the difference between grouping organisms by morphology
and relatedness?
What does it mean to group things hierarchically?
Why do we use the Linnean hierarchy, if only ‘species’ are biologically relevant?
And what does that mean?
Can you assign all the organisms you have seen to the correct domains,
kingdoms, and phyla - and whether they are pro- or eukaryotic?
…and of course, the display boards… :)