ALGAE LAB KEY

Original Document: Algae Lab

Prelab Questions

1. Algae belong to what Kingdom? ___Protista___
2. What are the three types of multicellular algae? red, green, brown algae
3. Are algae autotrophs or heterotrophs? _______autotrophs________
4. What organelle allows plants (and plantlike protists) to photosynthesize? _____chloroplasts_____

Euglena

1. Use the scanning lens to focus the slide. At this point, euglena will appear as small green dots. Estimate how many you see in your viewing field under this magnification: ___~500 (answers vary)_____

2. Focus using the low power objective. Estimate how many euglena you see now: ___~100 (answers vary)_
3. Focus using the high power objective. Estimate how many euglena you see now: ___~10 (answers vary)________

4. The microscope's magnification is probably not powerful enough to see the euglena's flagella. What is the purpose of the flagella? ____movement___

5. The euglena also move by scrunching up or rolling into a ball. This type of movement is called EUGLENOID MOVEMENT. Locate a euglena and watch it to see if you can recognize this special type of movement. (check box)

6. Darken half your viewing field. You can do this by placing dark paper over the microscope's light, or you can rotate the diaphragm slightly (not clicked into place). The goal is to have a "half-moon" dark spot on your slide. View the euglena as they interact with this dark area. Describe your observations.

(answers vary) Ideally, the euglena will move toward the light

7. Sketch the euglena. LABEL the chloroplasts, cell membrane (pellicle) and the eyespot.

Spirogyra

8. View a slide of spirogyra under scanning, low power, and high power. On one filament of spirogyra, estimate how many cells are present: ______Approximately 20-30 on a single strand

9. Sketch the spirogyra. LABEL the chloroplasts and the cell wall.

 

Volvox

10. View the volvox under scanning and low power. Sketch the volvox.

 

Post-Lab Analysis

11. Compare and Contrast each of the 3 Algae you looked at by filling out a Venn Diagram (you should be able to come up with at least 3 items for each group)