1. Microscopes and the Cell
Describe how the different types of microscopes work.
Distinguish between prokaryotes and eukaryotes.
Determine what Differentiated and Stem Cells are.

2. Light Microscopes
A typical light microscope allows light to pass through a specimen and uses two lenses to form an image.
Because light waves are scattered as they pass through matter, light microscopes can only magnify objects 1000x.

3. Electron Microscopes
Electron microscopes offer much higher resolution than light microscopes. But MUST be used in a vacuum, so only NONLIVING specimens can be studied.
There are two major types of electron microscopes:
transmission
scanning.

4. Transmission Electron Microscopes
Transmission electron microscopes produce flat, two-dimensional images.
Mag ~ 50-1 mill. x
$ $30,000- $500,000

5. Scanning Electron Microscopes
Scanning electron microscopes produce three-dimensional images of the specimen’s surface.
Mag ,000x
$150,000

6. Prokaryotes and Eukaryotes Review
Eukaryotes are cells that enclose their DNA in a nucleus.
Prokaryotes are cells that do not enclose their DNA in nucleus.

7. Prokaryotes
Prokaryotic cells are generally smaller and simpler than eukaryotic cells. Prokaryotic cells also evolved prior to Eukaryotic cells.
The organisms we call bacteria are prokaryotes.

8. Eukaryotes
Eukaryotic cells are generally larger and more complex than prokaryotic cells.
Most eukaryotic cells contain dozens of structures and internal membranes.
There are many types of eukaryotes: plants, animals, fungi and protists.

9. Differentiated Cells
Cell differentiation is relevant to multicellular organisms only. It is how generic embryonic cells become specialized cells. This occurs through a process called gene expression.
Gene expression is the specific combination of genes that are turned on or off (expressed or repressed), and this is what determines how a cell functions.

10. Stem Cells
A Stem Cell is an undifferentiated cell, of a multicellular organism, that is capable of giving rise to infinitely more cells of the same type, and from which certain other kinds of cell arise by differentiation.
Totipotent – can become ALL cells
Pluripotent – can become cells of the body NOT placenta or its support structures.
Multipotent – adult stem cells, can give rise to a limited number of cell