Biology, Answering the Big Questions of Life/Cells and the Microscope

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Cells and the Microscope[edit]

Phase contrast microscope labelled1.jpg

All living organisms are made up of subunits called cells. Most cells are too small for the human eye to see, so we must use microscopes to see them.

The most common type of microscope used in biological labs is the compound light microscope. In this laboratory we will look at different types of cells under the light microscope.

In this laboratory we will learn to use the microscope. We will look at prepared slides and make "wet mounts". We will observe the differences in appearance between cells of different Kingdoms, and we will identify organelles visible with the light microscope.

GOALS

  1. Identify the parts of the microscope.
  2. Learn to use microscope.
  3. Learn to make a wet mount.
  4. Draw and identify cells belonging to: Bacteria, Protists, Fungi, plants, and Animals.
  5. Learn to identify plant organelles in the microscope.
  6. Observe Osmosis in plant cells.

To Do:

A. Identify the parts of the microscope

B. Animal cells Follow instructions. Draw cheek cell / list total magnification on all drawings

C. Onion epidermis cells Prepare slide following instructions Draw cells

D. Cell Plasmolysis Draw plant cell before and after plasmolysis

E. Observe cells from the different kingdoms Draw a cell of each type excluding archea

The Microscope is used to magnify stuff

Directions for microscope use[edit]

1. Plug in and turn on the lamp. Turn the light to a medium high power.

2. Make sure that the lowest powered objective lens is down. Lower the stage to its lowest setting.

3. Position the slide in the clamps. Use the stage controls to make sure that the image is centered. It should be positioned below the objective and in the path of the light.

4. If a condenser is present, set the aperature dial on the lowest setting. (smallest opening).

5. Looking in the eyepiece, slowly move the coarse adjustment knob to find the specimen. If you are unsure that you are looking at the slide, move the slide from side to side. If the specimen is thick, begin by focusing on the side of the specimen and then moving the slide to the center.

6. Adjust the light for the best viewing using the condensor knob, and the light level controls.

7. To use a higher powered objective, click the new objective into position, and then refocus using the fine adjustment knobs. Always look when turning objectives to prevent crashing the lens into the slide.

8. When you are in focus, use the stage controls to scan the field and find a good example to observe.