Bio 101 ch. 30

soredia

A billionaire buys a sterile volcanic island that recently emerged from the sea. To speed the arrival of conditions necessary for plant growth, the billionaire might be advised to aerially sow what over the island? a. soredia b. spores of ectomycorrhizae c. basidiospores d. yeasts

ascomycete, ascocarp, ascus, ascospore

Arrange the following in the order from largest to smallest. a. ascomycete, ascocarp, ascus, ascospore b. ascomycete, ascus, ascospore, ascocarp c. ascocarp, ascus, ascospore, ascomycete d. ascocarp, ascomycete, ascus, ascospore

It should produce fewer fermentation products per unit time.

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? a. It should produce fewer fermentation products per unit time. b. It should have reduced motility. c. It should have a smaller nucleus. d. It should be transcriptionally less active.

plasmogamy

At which stage of a basidiomycete's life cycle would reproduction be halted if an enzyme that prevented the fusion of hyphae was introduced? a. germination b. karyogamy c. plasmogamy d. fertilization

haploid

Fungi produce _____ spores. a. dikaryotic b. heterokaryotic c. haploid d. diploid e. triploid

fungal enzymes

When a mycelium infiltrates an unexploited source of dead organic matter, what are most likely to appear within the food source soon thereafter? a. increased oxygen levels b. fungal haustoria c. larger bacterial populations e. fungal enzymes

flagellated spores

Which feature seen in chytrids supports the hypothesis that they diverged earliest in fungal evolution? a. parasitic lifestyle b. flagellated spores c. the absence of chitin within the cell wall d. coenocytic hyphae

results in heterokaryotic or dikaryotic cells

In most fungi, karyogamy does not immediately follow plasmogamy, which consequently _____. a. results in heterokaryotic or dikaryotic cells b. allows fungi to reproduce asexually most of the time c. means that sexual reproduction can occur in specialized structures d. results in multiple diploid nuclei per cell

diploid zygote

Karyogamy produces a _____. a. diploid zygote b. haploid zygote c. spores d. mycelium e. hypha

decomposers

Most fungi are _____. a. photoautotrophs b. decomposers c. herbivores d. carnivores e. chemoautotrophs

heterokaryotic cells or dikaryotic cells

Plasmogamy can directly result in which of the following? a. heterokaryotic cells or dikaryotic cells b. heterokaryotic cells or cells with two diploid nuclei c. cells with a single haploid nucleus or dikaryotic cells d. dikaryotic cells or cells with two diploid nuclei

The organism saves energy during cell division because fewer DNA bases must be duplicated

The Neurospora genome is quite compact, lacking many of the noncoding DNA sequences that occur in humans and many other eukaryotes. Which of the following are probable benefits of the compactness of the genome? a. It is more difficult for viruses to insert themselves into a compact genome. b. The organism saves energy during cell division because fewer DNA bases must be duplicated. c. The spores will be small and thus travel a greater distance. d. There is less genetic variation that can lead to mutation.

C

The process indicated by the letter ______ produces a diploid sturcture. A B C D E

by flagella

Use the following information to answer the question(s) below. For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection. Apart from direct amphibian-to-amphibian contact, what is the most likely means by which the zoospores spread from one free-living amphibian to another? a. by wind-blown spores b. by hyphae c. by cilia d. by flagella

Deuteromycetes

Use the following information to answer the question(s) below. For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection. Sexual reproduction has not been observed in Bd. If its morphology and genetics did not identify it as a chytridiomycete, then to which fungal group would Bd be assigned? a. basidiomycetes b. glomeromycetes c. deuteromycetes d. zygomycetes

hyphae

Use the following information to answer the question. In the United States and Canada, bats use one of two strategies to survive winter. They either migrate south, or they hibernate. Recently, those that hibernate seem to have come under attack by a fungus, Geomyces destructans (Gd), an attack that is occurring from Missouri to New England, Canada, and even the state of Washington. Many infected bats have a delicate, white filamentous mat on their muzzles, which is referred to as white-nose syndrome (WNS). The fungus invades the bat tissues, causes discomfort, and awakens the bat from its hibernation. The bat fidgets and wastes calories, using up its stored fat. The bat then behaves abnormally, leaving its cave during daytime in winter to search for food. Their food, primarily insects, is scarce during the winter, and the bats ultimately starve to death. Since 2006, it is estimated that over six million bats have perished from WNS. The Gd mat on the fur of the bats should be expected to consist of ________. a. haustoria b. yeasts c. hyphae d. basidia

A

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 is the mycelium currently absorbing the most nutrients per unit surface area, per unit time? A B C D

C

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. What is the most probable location of the oldest portion of this mycelium? A B C D

DNA sequence

Which of the following characteristics would be most helpful in distinguishing among different species of fungi? a. DNA sequence b. morphology c. life cycle d. hyphae structure

meiosis

Basidia produce spores by a process known as _____. a. decomposition b. mitosis c. meiosis d. hyphae e. binary fission

Ascomycota

Cup fungi are in the phylum _____. a. Zygomycota b. Chytridomycota c. Ascomycota d. Chordata e. Basidiomycota

restoration of the ability to form mycorrhizae with fungi by a flowering plant after biologists transferred a gene from a liverwort to the flowering plant

Early fungi probably formed mutualistic associations with early plants, providing nutrients to the plant and receiving energy-containing compounds. Evidence that plants' ability to form a mutualistic association with fungi is due to ancient genes includes which of the following occurrences? a. presence of genes in the earliest fungi that showed an ability to digest cellulose and lignin b. presence of genes for chitin in the oldest flowering plants and oldest fungi c. restoration of the ability to form mycorrhizae with fungi by a flowering plant after biologists transferred a gene from a liverwort to the flowering plant d. fossils that show hyphae wrapped around seeds

colonization of land and loss of flagellated cells

Fossil fungi date back to the origin and early evolution of plants. What combination of environmental and morphological change is similar in the evolution of both fungi and plants? a. colonization of land and loss of flagellated cells b. periods of drought and presence of filamentous body shape c. presence of "coal forests" and change in mode of nutrition d. predominance in swamps and presence of cellulose in cell walls

The high ratio allows for more material to be acquired from the surroundings and transported through the cell membrane.

Fungi have an extremely high surface-to-volume ratio. What is the advantage of this characteristic to an organism that gets most of its nutrition through absorption? a. The high ratio allows for more material to be acquired from the surroundings and transported through the cell membrane. b. The lower volume prevents the cells from drying out too quickly, which can interfere with absorption. c. This high ratio means that fungi have a thick, fleshy structure that allows the fungi to store more of the food it absorbs. d. This high ratio creates more room inside the cells for additional organelles involved in absorption.

a fungus that is raised by ants on leaves that the ants collect from trees and shrubs.

Fungi interact with many organisms in mutualistic ways. Which of the following involves a fungus that is mutualistic with another organism? a. a fungus that produces penicillin that is used by humans to kill infectious bacteria b. a fungus that lives inside plant roots and produces toxins that kill neighboring plants c. a fungus that is raised by ants on leaves that the ants collect from trees and shrubs d. a fungus and a protozoan that live together as a lichen

Surroundings

Fungi release digestive enzymes into their _____. a. surroundings b. gastrovascular cavity c. stomach d. hyphae e. mycelia

Discover the lignin-digesting enzymes of fungi, and use them to digest plant tissues left over from food-crop residues and produce a biofuel.

If you wanted to use fungi to improve the environment, which of the following research goals would make the most sense? a. Discover the enzymes that fungi use to break down plant matter and use them to increase decomposition rates in order to slow global warming. b. Discover the lignin-digesting enzymes of fungi, and use them to digest plant tissues left over from food-crop residues and produce a biofuel. c. Discover the enzymes that the fungal partner in lichens uses to break down rock so that large rock expanses can be turned into agricultural lands. d. Develop a strain of fungus that produces enzymes that absorb oxygen and will help slow global warming.

Radioactively labeled sugars produced by plants eventually show up in the fungi with which they are associated.

It has been hypothesized that fungi and plants have a mutualistic relationship because plants make sugars available for the fungi's use. What is the best evidence in support of this hypothesis? a. Fungi survive better when they are associated with plants. b. Fungi associated with plants have the ability to undergo photosynthesis and produce their own sugars, while those not associated with plants do not produce their own sugars. c. Radioactive labeling experiments show that plants pass crucial raw materials to the fungus for manufacturing sugars. d. Radioactively labeled sugars produced by plants eventually show up in the fungi with which they are associated.

leaf mesophyll

Mycorrhizae are to the roots of vascular plants as endophytes are to the ________ of vascular plants. a. leaf mesophyll b. stem apical meristems c. root apical meristems d. xylem

a. b. c. d. e.

Part A - Structure of multicellular fungi This diagram shows the structure of a multicellular fungus, with an expanded view of two types of hyphae. Identify the structures and determine which hypha is septate and which is coenocytic. (Note that although this diagram shows the two types of hyphae, a fungus can have either one type or the other, but not both.) {picture} Drag the labels to their appropriate locations on the diagram of the fungus and hyphae below. 1. mycelium 2. septate hypha 3. coenocytic hypha 4. pore 5. septum

Some fungi can grow as either filamentous or single-celled forms. Mycelia are made up of small-diameter hyphae that form an interwoven mass, providing more surface area for nutrient absorption. All fungi are heterotrophs; some species live as decomposers and others a symbionts. Some fungi secrete digestive enzymes into enviornment and then absorb the digest nutrients.

Part B - Fungal morphology and physiolo The following statements describe something about the body structures or functions of fungi. Identify those statements that are correct. Choose all that apply. a. Some fungi can grow as either filamentous or single-celled forms. b. Mycelia are made up of small-diameter hyphae that form an interwoven mass, providing more surface area for nutrient absorption. c. All fungi are heterotrophs; some species live as decomposers and others as symbionts. d. Some fungi secrete digestive enzymes into the environment and then absorb the digested nutrients. e. Cellulose gives rigidity and strength to the cell walls of fungi. f. Nutrients can flow through the entire mycelium in fungi with coenocytic hyphae, but not in fungi with septate hyphae.

Decomposers: fungi in assoication with a fallen log, fungi in association with a dead rabbit, coprophilous fungi Mutualist: mycorrhizal fungi on pine tree roots, fungi in the family Lepiotaceae Parasite: Tichophyton spp., Cryphonectria parasitica, Cordyceps spp., Septobasidium spp. and an individual scale insect infected by fungal hyphae

Part C - Ecological interactions of fungi Sort the following fungi based on whether they are decomposers, mutualists, or parasites. 1. fungi in association with a fallen log 2. fungi in association with a dead rabbit 3. coprophilous fungi 4. mycorrhizal fungion pine tree roots 5. fungi in the familyLepiotaceae 6. Trichophyton spp. 7. Cryphonectria parasitica 8. Cordyceps spp. 9. Septobasidium spp. and an individual scale insect infected by fungal hyphae

B

Plasmogamy is indicated by the letter _____. A B C D E

mutualistic

SOme fungal species live in plants and can kill herbivores that feed on the plant. What type of relationship does this fungus have with its host? a. predatory b. parasitic c. mutualistic d. commensal

Does nitrogen fertilization of crops affect the likelihood that Arthrobotrys will trap and kill nematodes?

Some nematode worms suck plant juices from the roots of plants and are economically important agricultural pests. Some fungi are usually decomposers of plant material, but some trap and kill nematodes at times. Arthrobotrys traps and kills nematodes, especially when they lack nitrogen sources. These two facts suggest that farmers could find Arthrobotrys an important tool in combating nematode infestations. Which of the following research questions would make a good starting point for developing such a defense against plant-sucking nematodes? a. What is the evolutionarily oldest method of trapping nematodes? b. What mechanisms do nematodes have that could allow them to escape from Arthrobotrys? c. Do nitrogen-fixing bacteria provide nitrogen to the fungi? d. Does nitrogen fertilization of crops affect the likelihood that Arthrobotrys will trap and kill nematodes?

determine how much each potential mutualist contributed to cell wall degradation

Use the following information to answer the question. Along with bacteria and protozoa, some chytrid fungi live in the digestive tracts of cattle and aid in the digestion of plant matter; thus, all three groups represent potential mutualists with cattle. In an experiment designed to test how much of a contribution to cell wall digestion was made by fungi in one part of the stomach (rumen), Lee et al. fed grain to cattle and then removed samples of the rumen contents. They took these samples to the laboratory and experimentally treated them with various chemicals to produce fractions that contained (A) only fungi, (B) only bacteria, (C) only protozoa, and (D) all of the potential mutualists. They then measured the percent of the cell wall that was degraded (see the figure). Degradation rates of cell walls extracted from Orchard grass by the monoculture system to assess the relative contributions of digestion by bacterial (square), protozoan (triangle), and fungal (diamond) systems, and all components (closed circle) as a control. The lowercase letters above the spots indicate statistical significance; mean values with different letters are significantly different (P < 0.05). Which of the following reasons provides the best explanation for the use of a control that contained all potential mutualists? Comparison to a fraction that contained all potential mutualists allowed the researchers to ________. a. demonstrate that their laboratory culture conditions allowed all potential mutualists to grow b. better mimic the conditions of the rumen c. determine how much each potential mutualist contributed to cell wall degradation d. demonstrate that the various potential mutualists did not compete with each other

No effect is predicted, because the dominant species is unaffected by AMF diversity.

Use the following information to answer the question. 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. Graph e is the total biomass (grams) of all 11 plant species combined; graph f is the biomass of Bromus erectus plants only, separated from the total. Based on graphs e and f, which is the most well-supported prediction for the effect on total plant biomass if AMF diversity were increased to eight species? a. No effect is predicted, because the dominant species is unaffected by AMF diversity. b. Total biomass for eight species would double in comparison to that for four species. c. Rare species would produce more biomass compared to the case when fewer AMF are present. d. No effect is predicted, because the dominant species is non-mycorrhizal.

Bromus erectus is unaffected by AMF diversity.

Use the following information to answer the question. 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. Graph e is the total biomass (grams) of all 11 plant species combined; graph f is the biomass of Bromus erectus plants only, separated from the total. What is the major difference between Bromus erectus (graph f) and the other plant species (graphs a-d) included in the study? a. Bromus erectus grows best with a diversity of fungal partners. b. Bromus erectus does not form mycorrhizal associations. c. Bromus erectus is unaffected by AMF diversity. d. Bromus erectus produces very little biomass regardless of AMF.

A toxin secreted by JI cells kills Bd cells when both are present together on frog skin

Use the following information to answer the question. For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection. However, when adult amphibian skin harbors populations of the bacterium Janthinobacterium lividum (Jl), chytrid infection seems to be inhibited. A researcher took water in which a Jl population had been thriving, filtered the water to remove all bacterial cells, and then applied the water to the skins of adult amphibians to see if there would subsequently be a reduced infection rate by Bd when frog skins were inoculated with Bd. For which of the following hypotheses is the procedure described a potential test? a. A toxin secreted by Jl cells kills Bd cells when both are present together on frog skin. b. Jl outcompetes Bd when both are present together on a frog's skin. c. The presence of Jl on frog skin causes a skin reaction that prevents attachment by Bd cells. d. Jl cells infect and kill Bd cells when both are present together on frog skin.

The fungal conversion from yeast to hyphal morphology allows such fast growth that the body's defenses are at least temporatily overwhelmed

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. Humans have immune systems in which lymph nodes are important, because many white blood cells (phagocytes and lymphocytes) reside there. Given that a successful infection by S. schenkii damages lymph nodes themselves, which of the following is most probable? a. The fungal conversion from yeast to hyphal morphology allows such fast growth that the body's defenses are at least temporarily overwhelmed. b. Defensive cells of humans cannot detect foreign cells that are covered with cell walls composed of cellulose. c. Given that most fungal pathogens attack plants, human defenses are simply not adapted to seek out and destroy fungi. d. The hyphae secrete antibiotics, which increases the ability of the infected human to tolerate the fungus.

S. schenkii should be reclassified; S. schenkii yeasts belonging to two different mating strains were introduced by the same thorn prick.

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? a. S. schenkii should be reclassified; S. schenkii yeasts belonging to two different mating strains were introduced by the same thorn prick. b. S. schenkii produces asexual spores within lymph nodes; S. schenkii yeasts belonging to two different mating strains were introduced by the same thorn prick. c. S. schenkii produces asexual spores within lymph nodes; it continues to have no known sexual stage. d. The hyphae growing in lymphatic vessels probably belonged to a different fungal species; S. schenkii yeasts belonging to two different mating strains were introduced by the same thorn prick.

If a single mycorrhizal fungus formed symbiotic associations with more than one tree, carbon could travel from one plant to another.

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. Based on the idea that fungi have pores between their cell walls that allow cytoplasm to move from one end of the mycelium to the other, which of the following hypotheses is the most plausible? a. Parasitic fungi steal nutrients from their hosts. b. Fungi function as part of the global carbon cycle, not only by converting carbon from one form to another, but by physically moving it from one location to another. c. Predatory fungi capture their prey by encircling them with hyphae, and the flowing of the cytoplasm through the pores helps the hyphae to move around the prey. d. If a single mycorrhizal fungus formed symbiotic associations with more than one tree, carbon could travel from one plant to another.

the cedar seedling, becuase it does not form ectomycorrhizal connections with the tested fungus

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. Referring to Simard et al. (1997), which design element is the control in this experiment and why? a. the cedar seedling, because it is not bagged b. the cedar seedling, because it does not form ectomycorrhizal connections with the tested fungus c. the fact that all the seedlings are different species d. the bags over the seedlings to contain the different types of carbon dioxide

no AMF are present

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 ________. a. AMF species A is present b. no AMF are present c. AMF species B is present d. AMF species C is present

Growth is best with AMF species A.

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. Examine the effect of AMF species on Sanguisorba officinalis. Which of the following conclusions can be correctly drawn from the data? a. Growth is best with AMF species D. b. Growth is best with a mixture of AMF species. c. Growth is best with AMF species A. d. AMF presence had no effect on S. officinalis growth.

D

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. Assume that all four locations are 0.5 meters 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? A B C D

fungicide might also kill mycorrhizae

When pathogenic fungi are found growing on the roots of grape vines, grape farmers sometimes respond by covering the ground around their vines with plastic sheeting and pumping a gaseous fungicide into the soil. The most important concern of grape farmers who engage in this practice should be that the _____. a. sheeting is transparent so that photosynthesis can continue b. lichens growing on the vines' branches are not harmed c. fungicide might also kill mycorrhizae d. fungicide might also kill the native yeasts residing on the surfaces of the grapes

the heterokaryotic stage of the fungal life cycle

Which of these contains two haploid nuclei? a. the heterokaryotic stage of the fungal life cycle b. zygote c. spore-producing structures d. mycelium e. hypha