Assignment 6 Due September 25

1. Essay (4 points) Observe the images and diagrams that compare cell and organelle sizes. Then write a short essay that answers the following questions:

How do most prokaryotes compare in size to small and large eukaryotic cells? How does a mitochondrion compare in size to a nucleus and to a prokaryote?

You might use statements such as “cell X is almost 20x bigger than cell Y” or you could use a ruler to obtain relative measurements. Try to incorporate information from both the images and the diagrams. Most importantly, your essay should make clear the magnitude of size differences.

2. Fill-in-the-blank (3 points 0.5 points each) Indicate whether each protist on page 1 of your assignment is more animal-like or plant- like (use these exact terms to receive credit).

Protist A ______

Protist B ______

Protist C ______

Protist D ______

Protist E ______

Protist F ______

3. Essay (3 points) Study the video of an ambiguous protist. Then write a short essay indicating why you think the protist is more animal-like or more plant-like. (Base you answer on observations of the protist.)

4. Essay (4 points) View the videos of two animal-like protists, then answer the following questions:

a) Describe the ways in which Stentor and Vorticella feed; what structures are involved in feeding?

b) Name, and briefly describe, one internal organelle in each protist.

Answer questions 5 and 6 based on the video of fungus.

5. Essay (3 points) Write a short essay that explains why the speaker refers to the mycelium of fungi as the world’s “first internet” (use at least two aspects of mycelium structure and/or function in your answer.)

6. Multiple-choice (1 point) According to the fossil record, how tall were the "giant" fungi that lived 400 million years ago?

6 inches 1 foot at least 3 feet at least 20 feet There were no giant mushrooms; these fossils are trees.

7. True or False (2 points--0.5 points each)

____ Fungal cells typically have haploid nuclei, except just prior to meiosis

____ Haploid nuclei from different fungal individuals (e.g., mom and dad equivalents) in some groups can coexist in the same cell without fusion.

____ The dikaryotic stage is part of the sexual cycle of Ascomycota, but not Basidiomycota.

____ Sacs containing 8 spores are typically found on Basidiomycota gills.

8. File upload (8 points) Construct a key for the 9 specimens in the fungi collection. Base your key on the photographs and videos of these specimens. You may start with the "student key" below or use a different approach. Submit your key to WebAssign as a doc or pdf file (pdf is preferred). NOTE: this is one of the few times that a doc or pdf file is acceptable.

Hints: Remember that your key is for identification of the 9 organisms provided in the collection. So the key must lead to the common name or scientific name of each species (not to group names like Ascomycetes). The slime mold is an exception, since we do not know its name.

First part of a student's key

1a. Having stalked reproductive structures that look like sporangia...... go to 2

b. Reproductive structures unlike that in 1a...... go to 3

2a. On microscopic examination, a mycelium is present...... go to 4

b. On microscopic examination, a mycelium is not present; the organism behaves like a huge amoeba...... slime mold