Microscopes

Learning Target

  • Use a Compound Microscope to predict and sketch different samples

Success Criteria

  • I can list different living organisms
  • I can draw what different samples look like at several times greater than the naked eye.

Cells

We are made of cells!

Cells are the basic building blocks of living things. The human body is composed of trillions of cells, all with their own specialized function.

Team Talk

What things have cells?

Where can we find different cells?

Cells are small!

How small is a cell? Click the button below to learn about the size of cells:

Parts of the Microscope

  • Eyepiece = 10x
  • Small Objective lens = 4x
  • Medium Objective lens = 10x
  • Big Objective lens = 40x


Microscope Lab - Part 1: Letter

What Will We Do?

We will determine the field of view of the microscope. - the term field of view refers to how much you can see of the object you are looking at under the microscope.

Procedure

  1. Choose your roles in your group.
  2. Gather materials from the teacher.
  3. Create a heading in your science notebook called "Microscope Lab."
  4. Use your metric ruler to measure the length of one side of a square of graph paper, and record it in millimeters.
  5. Write a lowercase letter in one square of the graph paper, cut it out and make sketch, with as much detail as possible what it looks like in your notebook. Label this as "Naked Eye."
  6. Now, put the square on the center of your slide. Important! - Always handle the slide by its edges! Add a drop of water and place a cover slip over it. Carefully put the edge of the cover slip into the edge of the water at a 45° angle. Gently drop it over the square of paper. Be careful when handling the cover slip because it can break easily.
  7. Place the slide on your microscope. Be sure to start with the lowest power objective. Move the slide until you see as much of the entire square as possible.
  8. In your notebook, draw a diagram of the whole square. Then draw a circle around as much of it as you can see under low power. Label this with the number of the lowest power on your microscope.
  9. Increase the magnification on your microscope to the next highest objective. Draw a diagram of what you see.
  10. Continue with each power level of your microscope.

Making Sense

Discuss the following with your group and answer in your science notebook. Use the communication sentence stems to facilitate your conversation.

  1. Did you see more or less of the square of graph paper under higher magnification?
  2. What happens to your field of view as you increase magnification?
  3. How did your field of view change between low power and the next highest objective?

Microscope Lab - Part 2: Cheek Cell

What Will We Do?

We will discover what we can find when we look inside our body.

Procedure

  1. Before you begin, make sure your slide and cover slip from part 1 are clean. Check that there are no fingerprints on them. If they are dirty, wash and dry them carefully.
  2. Get materials from your teacher.
  3. Place a small drop of methylene blue stain on your slide.
  4. Gently scrape the inside of your cheek with the flat side of the toothpick. Scrape gently! Stir the end of the toothpick into the stain, and throw the toothpick away.
  5. Place one edge of the cover slip at the edge of the stain at a 45° angle. Gently lower it onto the slide. If there are any air bubbles, no matter how small, wash your slide and make a new one. It is important that you have a good slide.
  6. Begin viewing your slide with the lowest power objective on your microscope. It is impor- tant to eliminate blurriness now so that it will be easier to focus as you increase the power. Draw what you see using each of the objectives on your microscope. Be sure to label the power of the objective you are using under each drawing.

Making Sense

Discuss the following with your group and answer in your science notebook. Use the communication sentence stems to facilitate your conversation.

  1. What do you think the things from the inside of your mouth are?
  2. Do you think you could find the same kind of thing in other parts of your body? Why?

From Molecules to Organisms