microscopes, cell theory. eyepiece arm objectives stage coarse focus fine focus diaphragm base
TRANSCRIPT
Microscopes, Cell Theory
EYEPIECE
ARMOBJECTIVES
STAGE
COARSE FOCUS
FINE FOCUSDIAPHRAGM
BASE
- Always carry microscope byARM and BASE.
- Always begin by finding image using
COARSE FOCUS.
- Use coarse focus only with LOW POWER.Otherwise, use fine focus.
- Magnification = Eyepiece x Objective
80x.
Ex. Eyepiece is 4x. Objective is 20x.
Overall magnification equals
Cell TheoryCell definition – the basic unit of structure and function for all living things.
onion blood
sperm and egg bacteria
What allowed us to discover cells?
Microscope http://micro.magnet.fsu.edu/primer/java/electronmicroscopy/magnify1/index.html
Cell Theory
Robert Hooke; 1665; cork cells. . . I could exceedingly plainly perceive it to be all perforated and porous, much like a Honey-comb, but that the pores of it were not regular. . . . these pores, or cells, . . . were indeed the first microscopical pores I ever saw, and perhaps, that were ever seen, for I had not met with any Writer or Person, that had made any mention of them before this. . .
Cell Theory
In the mid-1800’s , Cell Theory was developed which states:
1. All living things are made of cells.
2. Cells are the basic unit of structure and function.
3. All cells come from pre-existing cells.
Cell Theory
Two different classes of cells:
1. Eukaryotes: have a nucleus;
plants and animals
2. Prokaryotes: no nucleus;
bacteria
Cell Theory
How big are cells?
1. Plants and animals: 10 – 50 micrometers
(millionths of a meter)
http://www.cellsalive.com/howbig.htm
2. Bacteria: 1 - 2 micrometers or less (less than 1/10th size
of plant and animal
cells)
Cell Theory
Can some cells live on their own?
Yes!
http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/stentor/t1/stentor08.html
http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/paramecium/t1/paramecium09.html
http://micro.magnet.fsu.edu/moviegallery/pondscum/protozoa/euglena/rostrifera/t1/rostrifera08.html
Cell TheoryCellular Organization
Simple complex1. Cell2. Tissue3. Organ4. Organ System
Many systems put together is an ORGANISM.