1 Review What is a cell Explain What three statements make up the cell

theory Infer How did the invention of the microscope help

the development of the cell theory2 Review How do microscopes work Apply Concepts What does it mean if a micrograph

is “false-colored”

CH 7 CELL STRUCTURE AND FUNCTION7.1 Life is Cellular

Robert Hooke 1665 used microscopes Looked in cork Used the word “cell.”

Anton van Leeuwenhoek Early master lens maker Made early microscopes Looked at pond water.

Cell Theory

1. The cell is the basic unit of life2. All living things are made up of at least one cell3. All cells come from other cells.

Compound Light Microscope Light waves pass through

small organisms or thin slices of larger ones

Up to 1500 times magnification

Ours magnify 400 times Used to see bacteria cells, and a few organelles.

Stains and Dyes Increases contrast and

detail Can see more

organelles.

Transmission Electron Microscope (TEM)

Magnifies up to 1 million times

Shows internal structures

Specimen has to be dead.

Scanning Electron Microscope (SEM)

Magnifies up to 1 million times

Shows the surface of the specimen

Used for cell surfaces, organelle membranes, viruses

Specimen may be living.

Cell Types

Eukaryote

Prokaryote

Prokaryotes

Lack nucleus Lack membrane bound organelles

Bacteria.

Eukaryotes

Have a nucleus Have membrane bound organelles

Everything but bacteria.

Nucleus

Contains the DNA Control center of cell.

Cell Membrane Plasma Membrane

Controls what goes in and out of cell Protective boundary Semi fluid

Similar to skin.