front 1 1) 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) hyphae D) basidia | back 1 A |
front 2 2) What do fungi and arthropods have in common? C) Both groups use chitin for support. | back 2 C |
front 3 3) 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? | back 3 A |
front 4 9) If all fungi in an environment that perform decomposition were to
suddenly die, then which group of organisms should benefit most, due
to the fact that their fungal competitors have been removed? B) protists | back 4 C |
front 5 10) When a mycelium infiltrates an unexploited source of dead organic
matter, what are most likely to appear within the food source soon
thereafter? C) increased oxygen levels | back 5 B |
front 6 11) A fungal spore germinates, giving rise to a mycelium that grows
outward into the soil surrounding the site where the spore originally
landed. Which of the following accounts for the fungal movement, as
described here? B) mycelial flagella | back 6 D |
front 7 12) 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 ________. | back 7 C |
front 8 13) The adaptive advantage associated with the filamentous nature of
fungal mycelia is primarily related to ________. C) the increased probability of contact between different mating
types | back 8 D |
front 9 14) 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? C) commensal | back 9 B |
front 10 23) Some companies advertise and sell mycorrhizae to home gardeners and commercial farms, claiming that the presence of mycorrhizae improves plant growth and survival. If the company conducted experiments on plants with and without mycorrhizae, which of the following measurements would support their claim? A) smaller apple size in plants with mycorrhizae than in plants
without mycorrhizae D) increased mortality in plants with mycorrhizae than in plants without mycorrhizae | back 10 B |
front 11 24) 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) Does nitrogen fertilization of crops affect the likelihood that
Arthrobotrys will trap and kill nematodes? D) What mechanisms do nematodes have that could allow them to escape from Arthrobotrys? | back 11 A |
front 12 25) At which stage of a basidiomycete's life cycle would reproduction
be halted if an enzyme that prevented the fusion of hyphae was
introduced? C) plasmogamy | back 12 C |
front 13 26) Deuteromycetes ________. B) are the group of fungi that have, at present, no known sexual
stage | back 13 B |
front 14 27) 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. 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? C) basidiomycetes | back 14 D |
front 15 28) Plasmogamy can directly result in which of the following? A) cells with a single haploid nucleus or dikaryotic cells D) dikaryotic cells or cells with two diploid nuclei | back 15 B |
front 16 29) After cytokinesis occurs in budding yeasts, the daughter cell has a ________. A) similar nucleus and more cytoplasm than the mother cell D) similar nucleus and less cytoplasm than the mother cell | back 16 D |
front 17 30) In most fungi, karyogamy does not immediately follow plasmogamy,
which consequently ________. C) allows fungi to reproduce asexually most of the time D) results in heterokaryotic or dikaryotic cells | back 17 D |
front 18 31) 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? B) It should be transcriptionally less active. C) It should have reduced motility. | back 18 A |
front 19 32) The ascomycete Brachiola gambiae parasitizes the mosquito Anopheles gambiae. Adult female mosquitoes must take blood meals for their eggs to develop, and it is while they take blood that they transmit malarial parasites to humans. Male mosquitoes drink flower nectar. If humans are to safely and effectively use Brachiola gambiae as a biological control to reduce human deaths from malaria, then which of the following statements should be correct? A) The ascomycete should not be harmful to other insects and must be
harmful to male mosquitoes, but not to female mosquitoes. | back 19 B |
front 20 33) Why are mycorrhizal fungi superior to plants at acquiring mineral nutrition from the soil? A) Hyphae are 100 to 1,000 times larger than plant roots. D) Fungi secrete extracellular enzymes that can break down large molecules. | back 20 D |
front 21 34) 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) presence of "coal forests" and change in mode of
nutrition C) predominance in swamps and presence of cellulose in cell walls D) colonization of land and loss of flagellated cells | back 21 D |
front 22 35) The multicellular condition of animals and fungi seems to have arisen ________. A) due to common ancestry D) by serial endosymbioses | back 22 B |
front 23 36) Which feature seen in chytrids supports the hypothesis that they
diverged earliest in fungal evolution? C) flagellated spores | back 23 C |
front 24 37) 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 ________. B) horizontal gene transfer C) paraphyletic evolution D) convergent evolution | back 24 D |
front 25 38) 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 | back 25 B |
front 26 39) 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. C) 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. | back 26 B |
front 27 40) 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? C) Basidiomycota | back 27 A |
front 28 41) Arrange the following in order from largest to smallest. A) ascomycete, ascocarp, ascus, ascospore D) ascocarp, ascus, ascospore, ascomycete | back 28 A |
front 29 42) Arrange the following in order from largest to smallest, assuming
that they all come from the same fungus. C) gill, basidiocarp, basidiospore, basidium, mycelium D) mycelium, basidiocarp, gill, basidium, basidiospore | back 29 D |
front 30 49) 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. 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? C) by cilia | back 30 B |
front 31 50) 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. When adult amphibian skin harbors populations of the bacterium
Janthinobacterium lividum (Jl), chytrid infection seems to be
inhibited. Which of the following represents the best experimental
design to test whether this inhibition is real? B) Inoculate infected amphibians with Jl and determine whether the
amphibians recover from infection by chytrids. | back 31 C |
front 32 51) 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. | back 32 A |
front 33 52) Diploid nuclei of the ascomycete Neurospora crassa contain 14
chromosomes. A single diploid cell in an ascus will undergo one round
of meiosis, followed in each of the daughter cells by one round of
mitosis, producing a total of eight ascospores. If a single, diploid
G2 nucleus in an ascus contains 400 nanograms (ng) of DNA, then a
single ascospore nucleus of this species should contain how much DNA
(ng), carried on how many chromosomes? | back 33 A |
front 34 53) Which of the following characteristics would be most helpful in
distinguishing among different species of fungi? C) DNA sequence | back 34 C |
front 35 59) 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? | back 35 A |
front 36 61) 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? B) The fungal conversion from yeast to hyphal morphology allows such
fast growth that the body's defenses are at least temporarily
overwhelmed. D) Given that most fungal pathogens attack plants, human defenses are simply not adapted to seek out and destroy fungi. | back 36 B |
front 37 62) If haustoria from the fungal partner were to appear within the
photosynthetic partner of a lichen, and if the growth rate of the
photosynthetic partner consequently slowed substantially, then this
would support the claim that ________. B) lichens are not purely mutualistic relationships D) soredia are asexual reproductive structures combining both the fungal and photosynthetic partners | back 37 B |
front 38 63) 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? B) spores of ectomycorrhizae C) soredia | back 38 C |
front 39 64) 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? A) by transferring some chloroplasts to the embryo in each seed B) by providing the seeds with water and minerals D) by strengthening the seed coat that surrounds each seed | back 39 C |
front 40 65) 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 produces asexual spores within lymph nodes; it
continues to have no known sexual stage. | back 40 C |
front 41 66) Which of the following best describes the physical relationship
of the partners involved in lichens? C) Photosynthetic cells are surrounded by fungal hyphae. D) Fungi grow on rocks and trees and are covered by algae. | back 41 C |
front 42 67) Mycorrhizae are to the roots of vascular plants as endophytes are
to the ________ of vascular plants. C) root apical meristems | back 42 A |
front 43 68) Fungi interact with many organisms in mutualistic ways. Which of
the following involves a fungus that is mutualistic with another
organism? C) a fungus that lives inside plant roots and produces toxins that kill neighboring plants D) a fungus that produces penicillin that is used by humans to kill infectious bacteria | back 43 B |
front 44 69) Fungi produce many compounds that humans are able to use
medically. How can you account for these compounds? C) The compounds probably provide a benefit to the fungi. D) The compounds are produced as a result of sexual reproduction and recombination. | back 44 C |
front 45 70) Truffles are the fruiting bodies of certain fungi whose mycelium grows below ground. The truffle is also underground and can be detected by many mammals, which eat the truffle and expel the spores with their feces. Which of the following statements is likely accurate with respect to this interaction? A) The truffle spores are probably wind dispersed. D) Truffle fruiting bodies are important in decomposition of wood. | back 45 B |
front 46 71) If you wanted to use fungi to improve the environment, which of
the following research goals would make the most sense? | back 46 A |
front 47 1) All fungi are | back 47 B |
front 48 2) Which of the following cells or structures are associated with asexual reproduction in fungi? A) ascospores D) conidiophores | back 48 D |
front 49 3) The closest relatives of fungi are thought to be the A) animals. D) slime molds. | back 49 A |
front 50 4) The most important adaptive advantage associated with the
filamentous nature of fungal mycelia is C) the increased chance of contact between mating types. | back 50 D |