Exam 31: Fungi

Use the information to answer the following question. The 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 meters below the soil surface. At which location should one find the lowest concentration of fungal enzymes, assuming that the enzymes do not diffuse far from their source and that no other fungi are present in this habitat?

In most fungi, karyogamy does not immediately follow plasmogamy, which consequently ________.

Use the following information to answer the question. Heterobasidion is a basidiomycete that contributes to mortality of trees. Kuhlman isolated 23 strains of Heterobasidion and applied them to 16 seedlings of 10 different tree species. Partial results of this experiment are shown in the table. % mortality of five host species from five Heterobasidion isolates Isolate Isolate Isolate Isolate Isolate Host 63 117 195 126 118 Slash Pine 50 69 94 100 94 Shortleaf Pine 75 56 94 94 100 Red Cedar 38 32 19 50 25 Yellow-Poplar 0 0 0 6 6 6 Sycamore 0 0 0 0 6 Which of the following conclusions can best be drawn from these results?

You observe the gametes of a fungal species under the microscope and realize that they resemble animal sperm. To which of the following groups does the fungus belong?

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?

What do fungi and arthropods have in common?

Use the following information to answer the question. The 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 meters below the soil surface. In which of the following human mycoses should one expect to find a growth pattern most similar to that of the mycelium that produced the fairy ring?

Use the information to answer the following question. The 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 meters below the soil surface. If the fungus that produced the fairy ring can also produce arbuscules, then which of the following is most likely to be buried at location "C"?

Use the following information to answer the question. Rose-picker's disease is caused by the yeast Sporothrix schenkii (S. schenkii). The yeast grows on the exteriors of rose-bush thorns. If a human gets pricked by such a thorn, the yeasts can be introduced under the skin. The yeasts then assume a hyphal morphology and grow along the interiors of lymphatic vessels until they reach a lymph node. This often results in the accumulation of pus in the lymph node, which subsequently ulcerates through the skin surface and then drains. Suppose that S. schenkii had initially been classified as a deuteromycete. Asci were later discovered in the pus that oozed from an ulcerated lymph node, and the spores therein germinated, giving rise to S. schenkii yeasts. Which of these statements make sense on the basis of this information?

Chitin is a long-chain polymer derived from glucose. It strengthens cell walls of fungi and the outer covering (exoskeleton)of arthropods (including crabs, shrimps, and insects). The presence of chitin in these groups is likely due to ________.

Which feature seen in chytrids supports the hypothesis that they diverged earliest in fungal evolution?

Deuteromycetes ________.

Asexual reproduction in yeasts occurs by budding. Due to unequal cytokinesis, the "bud" cell receives less cytoplasm than the parent cell. Which of the following statements should be an accurate characterization of the smaller cell until it reaches the size of the larger cell?

The closest relatives of fungi are thought to be the

Which of the following characteristics would be most helpful in distinguishing among different species of fungi?

Which of the following best describes the physical relationship of the partners involved in lichens?

If you wanted to use fungi to improve the environment, which of the following research goals would make the most sense?

Use the following information to answer the question. There is much discussion in the media about protecting biodiversity. But does biodiversity really matter? Canadian and Swiss researchers wanted to know if the diversity of arbuscular mycorrhizal fungi (AMF)was important to the productivity of grasslands (M.G.A. van der Heijden, J. N. Klironomos, M. Ursic, P. Moutoglis, R. Streitwolf-Engel, T. Boler, A. Wiemken, and I. R. Sanders. 1998. Mycorrhizal fungal diversity determines plant biodiversity, ecosystem variability, and productivity. Nature 396:69-72). Specifically, they wanted to know if it mattered which specific AMF species were present, or just that some type of AMF was present. They grew various plants in combination with one of four AMF species (A, B, C, and D), no AMF species (O), or all four AMF species together (A + B + C + D); and they measured plant growth under each set of conditions. All plant species were grown in each plot, so they always competed with each other, with the only difference being which AMF species were present. On the graphs, the x-axis labels indicate the number and identity of AMF species (bar 0 = no fungi; bars A - D = individual AMF species; bar A + B + C + D = all AMF species together). The y-axis indicates the amount (grams)of plant biomass for the species shown in italics above each graph. Based on the van der Heijden et al. (1998)graphs in the figure, which of the following is the best description of the data supporting the idea that a plant species did not form mycorrhizae with a fungus? Its biomass is greatest when ________.

Use the following information to answer the question. Suzanne Simard and colleagues knew that the same mycorrhizal fungal species could colonize multiple types of trees. They wondered if the same fungal individual would colonize different trees, forming an underground network that potentially could transport carbon and nutrients from one tree to another (S. Simard et al. 1997. Net transfer of carbon between mycorrhizal tree species in the field. Nature 388:579-82). Pots containing seedlings of three different tree species were set up and grown under natural conditions for three years (Fig. A). Two of the three species (Douglas fir, birch)could form ectomycorrhizal connections with the same fungal species, but the third species (cedar)could not form an ectomycorrhizal connection with the fungal species. In some of the pots, the researchers placed airtight bags over the Douglas fir and birch seedlings and injected carbon dioxide made from carbon-13 into the bags with the Douglas fir and carbon dioxide made from carbon-14 into the bags with the birch. (13C and 14C are different isotopes of carbon that can be detected and measured by researchers.)As the seedlings photosynthesized, the carbon dioxide was converted into sugars that could be tracked and measured by the researchers. The researchers measured whether the sugars in each plant contained only the carbon isotope that was in the air of their plastic bag or also the carbon isotope from the air around the other plant. Figure A

The most important adaptive advantage associated with the filamentous nature of fungal mycelia is