Name: ______

Compound Light Microscope & Human Body Tissues Lab Academic

Purpose: To identify the parts of the compound light microscope and their functions, to demonstrate proper usage of the microscope and to learn how to make a wet mount slide.

Part 1:Preparing the Microscope for Use:

Materials: Microscope, Lens Paper, newspaper, water, coverslip, tissue prepared slides, scissors, dropper, beaker, dissecting needle.

Procedure:

The following is a list of steps that should be followed in the order given each time the microscope is used.

  1. Always carry the microscope with both hands. Grasp the arm of the microscope in one hand and place your other hand under the base. Always hold the microscope in an upright position so that the eyepiece cannot fall out.
  1. Place the microscope on a worktable or desk at least 10 cm from the edge. Position the microscope with the arm facing you.
  1. Record the number of your microscope ______. Compare your assigned microscope to the microscope diagram below. Using your textbook (pg. 1054) label the parts of the microscope in the picture below.

  1. Turn the coarse adjustment knob toward you so that the body tube comes all the way up. Rotating the nosepiece, note the magnifying powers of the objective lenses.
  1. Examine the eyepiece and find the magnifying power of that lens, which should be 10x. Remember that when viewing objects under the compound microscope you are viewing them through 2 lenses, the eyepiece and the objective. To determine your total magnification, you multiple the eyepiece magnification by the objective magnification. Complete the data table below.

Objective Lens / Eyepiece Magnification / Objective Magnification / Total Magnification
Low Power
Medium Power
High Power
  1. Use a piece of clean lens paper to wipeoff the face of the condenser, the stage, and other parts of the frame.
  1. Using a piece of clean lens paper, wipe the top lens of the ocular and the lenses at the tips of each ocular. Wipe the lenses gently and in one direction.
  1. Look through the eyepiece keeping both eyes open to avoid eyestrain. You should see a white circle of light; this is your field of view. Practice adjusting your diaphragm to permit varying amounts of light through.
  1. Turn the low-power objective into line with the body tube. When it is in proper position it will click.
  1. Open the diaphragm to the largest opening so that the greatest amount of light is admitted.
  1. Put your eye to the eyepiece. There should be a uniform circle of light without any shadow. This is the field. If specks or smudges appear in the field, either the lenses of the ocular or the tip lens of the objective is not clean. Using clean lens paper, wipe the lenses. Consult your teacher if it is necessary to remove the ocular for cleaning. When a clear field of bright light is obtained, the microscope is ready for use.

Conclusion Questions:

  1. What happened as you adjusted the diaphragm? What is its purpose? ______

______

  1. If you move from low to medium or high power and you see darkness, what went wrong? Hint: think about what you are physically doing.

______

______

Part 2: Tissues: Organ systems are made of organs, and organs are made of layers of cells called tissues

Purpose: You will not be viewing tissues, but must fill in the answer below (page 840-841 in your book.)

  1. What is a tissue? ______
  1. List the four functions of the following tissues:
  1. Nervous: ______
  1. Epithelial:______
  1. Muscular:______
  1. Connective:______
  1. A collection of tissues are used to build ______

Part 3:Preparing a WetMount Slide

Materials: scissors, printer paper square, glass slide, cover slip, eye dropper, 50 mL beaker and water

Procedure:

  1. Use a pair of scissors to cut a square the size of the box to the right of this sentence.
  1. Using a pen, write a sentence or phrase on the paper (Appropriate).

Write it as small as you can.

  1. Use an eye dropper to place one drop of water on the cut piece of newspaper.
  1. Using your thumb and pointer finger grab the coverslip by its sides.

Place thumb Place pointer finger

Cover Slip

  1. Place one end of the coverslip at the edge of the water on your glass slide. Slowly lower the coverslip over the water until it is flat against the glass slide.

*It is like when a castle lowers a draw bride to let visitors in.

  1. This will prevent any air bubbles from forming under the coverslip. You have just made a wet mount slide.
  1. If air bubbles appear gently remove coverslip and repeat step 4.

Part 3:Viewing your wet mount slide!

Materials: wet-mount slide, microscope

Procedure:

  1. Swap your wet mount slide with someone else’s slide. DO NOT read the message they have written on it.
  1. Without reading the message, center the wet-mount on the stage. NOTE: make sure the bottom of the slide is dry before you place it on the stage.
  1. Turn the low-power objective (4x) into position and bring the slide into focus. Draw & label the slide as seen through the microscope at LOW POWER.
  1. On the line below, write the name of the person who you switched slides with, and write the message. Hint: You may have to rotate the slide 180 Degrees to read the message.
  1. Turn the medium-power objective (10x) into position. Listen for a click as it sets into place. Bring the slide into focus using the fine adjuster, NOT THE COARSE ADJUSTER.
  1. Draw & Label the slide as seen through the microscope at MEDIUM POWER.

Conclusion Questions:

  1. Make a general statement about what happens to the letters on the paper image when you physically move it to the right? Left? Up? Down? ______

______

  1. How do the letterslook when viewed under the microscope at low power compare to how it looked when you placed it on the microscope stage? Provide drawings below comparing the two different images. ______

______

Name: ______March, 2012

Plant, Animals and Protists Cells Lab

Purpose: to create wet-mount slides and view self-prepared slides of human cheek cells, plant cells (elodea and onion cells) from living organisms and, describe the basic characteristics they have in common and describe their differences.

Pre-lab questions:use your text book (chapter 7) to help you answer the following questions.

  1. List the three parts of the cell theory:
  2. ______
  1. ______
  1. ______
  1. What is a cell? ______
  1. Cells that a similar in function, are used to build ______.
  1. How is a eukaryotic cell different from a prokaryotic cell? ______

______

______

  1. What type of cells are cheek epidermal cells, elodea cells and onion cells? (Prokaryotic or Eukaryotic)
  1. What is an organelle? ______

______

  1. Describe the function of the following organelles:
  1. Cell Membrane - ______
  1. Cytoplasm - ______
  1. Ribosome - ______
  1. Nucleus - ______
  1. Cell Wall - ______
  1. Mitochondria - ______
  1. Chloroplast - ______
  1. Vacuole - ______
  1. Based on the organelles listed in question 7, which ones are ONLY found in plant cells?

______

  1. How do the membrane-bound organelles of a eukaryotic cell act in a manner similar to the organs in a multicellular organism? ______

______

______

Procedure:

Cheek Epithelial cell:

1)Gently rub a clean toothpick along the inner lining of your cheek for approximately 30 seconds.

2)Rub the toothpick on a slide, place a drop of methylene blue on the spot, and place a coverslip on top.

3)Observe the cell at high power. Draw and label the cell membrane, cytoplasm, and the nucleus.

Elodea leaf:

1)Remove a young leaf from the tip of the plant.

2)Place the leaf on a slide, add a drop of water and place the coverslip on top.

3)Observe the slide under the microscope at the highest magnification possible. Select and draw one or two cells drawing and labeling the cell wall and cytoplasm. Find and label the oval, green chloroplasts. If they are moving, use arrows to indicate the direction.

4)The vacuole is like a clear water-filled balloon at the center on the cell. What evidence do you see of the vacuole? Label the area where the vacuole is found in your drawing.

Living Specimens (Euglena, Paramecium, Stentor, Volvox, and Amoeba):

1)Using a dropper, transfer a sample from the cultures at the front of the room onto a depression slide and place a coverslip on top. Remember to take note of the name of the specimen.

2)Observe and sketch under the highest magnification possible. Remember, these are living organisms and will be moving around. You may have to make several slides before you find a specimen to observe. Also, you will have to sketch quickly, as they tend to move in and out of your field of view.

3)Repeat for the remaining live specimens.

Conclusion Questions:

  1. Why must objects viewed with the compound light microscope be thin?
  1. Why did you need to use iodine on the cheek epidermis cells and the onion skin cells?
  1. In the mouth, your skin cells are connected together in a sheet. Why are they scattered on your slide?
  1. How did the unicellular organisms differ from single cells in a multicellular organism? Why? Give at least 2 specific examples in your answer.
  1. Volvox “straddles the fence between colonial and multicellular life.” Explain this statement fully supporting with examples.
  1. Explain the term cell specialization. In what types of organisms will you find cell specialization? Why?
  1. How would humans’ lives be different if we had chloroplasts in our skin? Explain.
  1. Explain why animals (like humans, for example) don’t need a cell wall?