1. Cells & Microscopes

2. Contributors to the Cell Theory
Robert Hooke (1665)
viewed cork cells under microscope; named cells
Anton van Leeuwenhoek (1673)
viewed living cells with a microscope

3. Mattias Schleiden (1838)
discovers that plants are made of cells
Theodor Schwann (1839)
discovers that animals are made of cells
Rudolf Virchow (1855)
stated that cells come only from other cells

4. The Cell Theory All organisms are composed of one or more cells.
Unicellular: one-celled
Multicellular: many-celled

5. The cell is the basic unit of organization of all organisms.
cells
organism
organ system
tissue

6. All cells come from preexisting cells.

7. Two Basic Cell Types Prokaryotes Simple Ex. bacteria
No membrane-bound organelles
No nucleus
Found only in unicellular forms
Ex. bacteria

8. Two Basic Cell Types Ex. algae, fungi, plants, animals Eukaryotes
Complex
Have membrane-bound organelles
Have a nucleus
Found in both uni- and multicellular forms

9. Cell Comparison

10. ALL Cells Have . . .
Cell membrane
Cytoplasm
DNA
Ribosomes

11. Introduction to the Microscope
Care
Parts
Focusing
Students will have their microscopes out, for reference as we go through each of the steps. As an introduction, students will be asked what kinds of things they can do with this tool.

12. Always carry with 2 hands Keep objects clear of desk and cords
Microscope Care
Always carry with 2 hands
Keep objects clear of desk and cords
Only use lens paper for cleaning
Do not force knobs
Always store covered
Teacher demonstrates how to hold the microscope, where the lens paper is located and how to use it. Students will be invited to turn the knobs and observe the stage as it moves up and down. Teacher will demonstrate how to store the microscope.

13. Microscope Parts Eyepiece Body Tube Revolving Nosepiece Arm
Objective Lens
Stage
Stage Clips
Coarse Focus
This is a similar version of the microscope used in class. Students will be identifying the parts on the microscopes at their desks as we go along and what their functions are.
Diaphragm
Fine Focus
Light
Base

14. Place the Slide on the Microscope Use Stage Clips
Using the Microscope
Place the Slide on the Microscope
Use Stage Clips
Start on Scanning (red) Power
Look into the Eyepiece
Use the Coarse Focus
Click nosepiece to Low (yellow) Power
Give students a slide from the “common things” set, each student will practice focusing and changing objectives.

15. Follow steps to focus using low power
Using High Power
Follow steps to focus using low power
Click the nosepiece to High (blue) power
Do NOT use the Coarse Focus Knob
Use the Fine Focus Knob to bring the slide in focus
Only some of the specimen may focus
Have students exchange slides so they can look at different things, walk them through using the high power objective to focus slides. Emphasize not using the coarse objective during this process, as it will crack the slides.

16. Total magnification = eyepiece x objective
Eyepiece magnifies 10x
3 different objectives:
Scanning (red) 4x total = 40x
Low (yellow) 10x total = 100x
High (blue) 40x  total = 400x

17. Drawing Specimens
Make detailed drawing of exactly what you see! Make sure the specimen is drawn to scale.
LABEL what you are observing AND the TOTAL magnification.
LABEL any structures to the side and connect to a line.

18. Example