Name______Date_____
Protist Lab
Wherever you find water, you will probably find eukaryotic, one-celled organisms called protists. Although protists are unicellular, they each perform the same life functions as multicellular plants and animals. Protists use food to produce energy, exchange gases, get rid of wastes, respond to their environment, and reproduce. Some protists are motile. In this lab, you will compare the structure, behavior, and methods of movement of representatives of three different protist phyla.
Day 1- Part A: Euglena
1. Place a drop of euglena culture on a clean glass slide. Cover the drop with a coverslip.
2. Using the low-power objective of your microscope, locate some euglena. Switch to the high-power objective.
Why is the low-power objective used to scan a slide rather than the
high-power objective?
______
3. Observe the euglena for several minutes. Study its structure and note its color and shape. Watch how the Euglena moves.
Describe the general shape of the euglena. ______
Describe the color of the euglena. What makes it this color? ______
How does the euglena obtain its food? ______
What is the function of the eyespot in the euglena? ______
How does the euglena move? ______
4. Draw the euglena under HIGH power.
Day 2- Part B: Amoeba
1. Take a drop from the bottom of the culture jar using the medicine dropper. Using the low-power objective, scan the slide until you locate an amoeba.
2. Observe the amoeba under low power.
3. Switch to the high-power objective and study how the amoeba moves.
Describe the amoeba’s shape and color. ______
How does the amoeba take in food? ______
How does the amoeba move? ______
Based on your observations, describe how the pseudopods form. ______
Is there a particular side of the amoeba that is always in the front of
the organism? Explain. ______
4. Put the low-power objective back in position. Move the slide so that the amoeba is in the center of the field. Leave the slide on the stage for five minutes. After this time, observe the amoeba, noting its shape and location.
After five minutes, is the amoeba still in the field of view? Is it still the
same shape? ______
5. Draw a picture of your amoeba in the circle below.
6. Clean the slide and throw out the coverslip.
Day 3- Part C: Paramecium
1. Place a drop of methylcellulose on a clean glass slide. Add a drop of paramecium culture and mix it with the methylcellulose. Cover with a coverslip.
Methylcellulose is a viscous, or thick, liquid. What do you think is the function of the methylcellulose in this Investigation Procedure?
______
The methylcellulose is only used with the paramecium. What does this
tell you about the amoeba and the euglena? ______
2. Using the low-power objective, scan the slide until you find a paramecium. Observe its structure, size, shape, and method of movement.
Describe the shape and color of the paramecium. ______
Explain how the paramecium moves. ______
Draw the paramecium under HIGH power.
3. Switch back to low-power.
4. Add a drop of carmine solution (food) to the edge of your coverslip. The carmine will seep under the coverslip into the culture.
5. Locate and observe a paramecium feeding on the carmine.
Describe how the paramecium takes in food. ______
6. Clean your slide and coverslip.
7. Before leaving the laboratory, wash your hands thoroughly with soap and water.
Protist comparison chart
Protist / Animal-like or Plant-like? / Producer orConsumer? / Method of
Movement / Method of food
getting
Euglena
Amoeba
Paramecium
ANALYSIS AND COMPARISON
1. What is a protist?
______
2. Which of the three protists from this lab are producers? Which are consumers? Explain your answer. ______
3. Of the three protists, the only one with an eyespot is a euglena. Why is this structure so important to this protist? ______
1