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Bio 182-General Biology

Activity 4: Protists (Exercises 25 & 26) Answer the questions in the space provided. You must submit this document on the date scheduled for this activity. Exercise 25: Procedure 25.1 (1-4). Draw a Chlamydomonas cell showing both flagella.

Question 1. C. How does methylcellulose (Protoslo) affect the movement of Chlamydomonas?

Question 1. D. How does the stigma help Chlamydomonas survive?

Procedure 25.3 (1-2, 4-7). #4 Draw your sketch of Spirogyra and note the shape of its chloroplasts using the 40X objective.

#7 Prepare a wet mount of Cladophora, then draw the general shape of Cladophora.

Question 3. A. Are the filaments of Spirogyra branched?

Question 3. B. What is the arrangement of the chloroplasts of Spirogyra?

Question 3. C. Compare live specimens of Spirogyra to the prepared slides. For which one was it easiest to see conjugation tubes? Draw them!

Question 3. D. Hypothesize how Spirogyra reproduces asexually.

Question 4. A. How is Cladophora morphologically similar to Spirogyra? How is it different?

Question 4. B. What is the shape of its chloroplasts?

Procedure 25.4. Volvox Draw your wet mount.

Question 5 A. What is oogamy?

Question 5 B. What are the tiny spheres inside the larger sphere of Volvox?

Question 5. C. How do you suppose they get out?

Question 5. D. How do you think the number of cells in a young Volvox colony compares to the number in a mature colony?

Procedure 25.5 (1-4). Phylum Phaeophyta: (Brown Algae) Read the information contained in your laboratory manual (pages 273-274) on Brown Algae. You will also need to look at the picture of the life cycle of Fucus. Then look at the specimens provided under the microscope. Question 6. A. How does the structure of Fucus differ from the green algae you examined earlier in this exercise?

Question 6. B. Are all portions of the thallus photosynthetic? How can you tell?

Question 6. C. Considering where Fucus lives, what do you think is the function of its gelatinous sheath?

Question 6. D. Are the swollen structures solid masses or are they empty, and how does this relate to their function?

Question 7. A. Are the gametes of Fucus isogamous or oogamous?

Question 7. B. How does the structure of tissue surrounding the reproductive structures compare with that of green algae?

Phylum Rhodophyta: (Red Algae) and Chrysophyta (Diatoms) Read the information contained in your lab manual Page 274 on Red Algae and Diatoms. Then do the following parts. Procedure 25.7 (3-5). Look at the red algae on display. How does it compare to the other algae you have observed?

Procedure 25.8 (2-5). Look at the diatoms and make a wet mount of some of them. Draw a diatom here.

Question 8. C. If diatoms lack flagella, how do you explain their motility?

Question 8. D. How would diatomaceous earth compare to sand as a material for swimming pool filters? Which would be better and why?

Procedure 25.10. Phylum Euglenophyta (Euglenoids) Question 10. What is the function of the eyespot in Euglena.

Phylum Rhyizopoda (Amoebas) Procedure 26.1 (1-4). Find a living Amoeba using the dissection scope, then use a pipette to obtain it, and make a wet mount of it. Draw the Amoeba.

Question 1. A. Can you detect moving cytoplasm in the extending pseudopodia of Amoeba?

Question 1. B. What do you suppose the living Amoeba is moving toward or away from?

Question 1. D. About how long would it take an Amoeba to move across the field of view on low power? Estimate.

Question 1. E. Why is a contractile vacuole of a protozoan often more difficult to see than a food vacuole?

Question 1. F. Why would excess water tend to accumulate in Amoeba?

Phylum Formanifera (Forams) Procedure 26.2 (1-2). Draw them here.

Question 2. How could fossilized forams in different geological layers of rock or sediment indicate the probability of finding oil?

Phylum Sarcomastigophora (Zoomastigotes) Look at the demo slides of Trypanosoma and Amoeba. Note comparisons for them here.

Question 3. A. How large is a Trypanosome relative to an Amoeba?

Phylum Ciliophora (Ciliates) Procedure 26.5 (1-4). Make a wet mount of Paramecium. Use Protoslo in order to make your observations. Then answer the following questions. Also look at the pictures of conjugating Paramecium on the bottom of page 284. Also Draw Paramecium here.

Question 4. A. Are cilia visible on living or prepared Paramecium?

Question 4. B. Does Paramecium rotate as it moves?

Question 5. B. Why is transverse fission not a sexual process?

Vorticella (1-4). Procedure 26.6. Look at the demo of Vorticella and draw it.

Question 6. A. What is the value or function of the rapid contraction of the stalk of Vorticella?

Question 6. B. What is the probable function of the moving cilia of Vorticella?