Exam 31: Fungi

Use the following information to answer the questions below. Recent genetic studies of the structure of microsporidian genomes, as well as the sequences of their tubulin genes and the gene for RNA polymerase II, indicate that microsporidians are closely related to the fungi. Microsporidians lack flagella, centrioles, peroxisomes, and mitochondria (although they do have degenerate mitochondria, called mitosomes). They have the smallest genome of any eukaryote, and it is a genome that changes quickly. The genome is contained within two haploid nuclei. All microsporidians are obligate intracellular parasites. They use a unique organelle called a polar filament to gain access to the cells of their hosts. One species causes chronic diarrhea in AIDS patients. Another parasitizes Anopheles gambiae, the mosquito that transmits a fatal form of malaria to humans. -Which of the following microsporidian features are shared with many other fungi? 1. chitinous cell wall 2. two haploid nuclei per cell 3. polar filament 4. chemoheterotrophy

Use the following information to answer the questions below. Unicellular yeasts can be represented as spheres, whereas filamentous hyphae more closely resemble cylinders. As these two geometric figures increase in size, their surface area-to-volume ratios change. The following tables demonstrate how this ratio changes, first for spheres, and second for cylinders. For the cylinder, girth (i.e., radius, r) will remain constant, whereas length, L, will increase. Note the formulas below the respective tables. A sphere's change in surface area and volume with increasing radius, r Area of a Sphere = 4r² Volume of a Sphere = 4/3r³ A cylinder's change in surface area and volume with increasing length, L Area of a Cylinder = 2(r²) + 2rL Volume of a Cylinder = r²ᴸ -Which statement is a correct interpretation of the data in the previous tables?

After cytokinesis occurs in budding yeasts, the daughter cell has a

What makes it risky to rely on the presence of chitin in adult amphibian skin as the sole positive test for the presence of chytrids?

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations A-D are all 0.5 metres below the soil surface. Responses may be used once, more than once, or not at all. -Assume that all four locations are 0.5 m above the surface. On a breezy day with prevailing winds blowing from left to right, where should one expect to find the highest concentration of free basidiospores in an air sample?

Which of these paired fungal structures are structurally and functionally most alike?

What accounts most directly for the extremely fast growth of a fungal mycelium?

Sexual reproduction has never been observed among the fungi that produce the blue-green marbling of blue cheeses. What is true of these fungi and others that do not have a sexual stage?

Orchid seeds are tiny, with virtually no endosperm and with miniscule cotyledons. If such seeds are deposited in a dark, moist environment, then which of the following represents the most likely means by which fungi might assist in seed germination, given what the seeds lack?

Among the organisms listed here, which are thought to be the closest relatives of fungi?

Immediately after karyogamy occurs, which term applies?

Which description does not apply equally well to both sexual and asexual spores?

Chemicals, secreted by soil fungi, that inhibit the growth of bacteria are known as

The vegetative (nutritionally active)bodies of most fungi are

Both fungus-derived antibiotics and hallucinogens used by humans probably evolved in fungi as a means to

The multicellular condition of animals and fungi seems to have arisen

Do cell walls of fungi differ from cell walls of plants?

Use the following information to answer the questions below. Unicellular yeasts can be represented as spheres, whereas filamentous hyphae more closely resemble cylinders. As these two geometric figures increase in size, their surface area-to-volume ratios change. The following tables demonstrate how this ratio changes, first for spheres, and second for cylinders. For the cylinder, girth (i.e., radius, r) will remain constant, whereas length, L, will increase. Note the formulas below the respective tables. A sphere's change in surface area and volume with increasing radius, r Area of a Sphere = 4r² Volume of a Sphere = 4/3r³ A cylinder's change in surface area and volume with increasing length, L Area of a Cylinder = 2(r²) + 2rL Volume of a Cylinder = r²ᴸ -As a direct result of increasing surface area in both yeasts and filamentous hyphae, which cell structures/materials must also increase? 1. amount of chitin 2. number of nuclei 3. amount of plasma membrane 4. number of mitochondria 5. amount of peptidoglycan

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations A-D are all 0.5 metres below the soil surface. Responses may be used once, more than once, or not at all. -At which location is the mycelium currently absorbing the most nutrients per unit surface area, per unit time?

What are the sporangia of the bread mould Rhizopus?