Microscopes, Cell Theory. EYEPIECE ARM OBJECTIVES STAGE COARSE FOCUS FINE FOCUS DIAPHRAGM BASE.

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.