CH 31 FUNGI STUDY GUIDE
Given the eukaryotic structures they lack, it should be expected that microsporidians also lack _____. A) the "9 + 2 pattern" of microtubules B) centrosomes C) lysosomes D) nuclei
A
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? A) 100, carried on 7 chromosomes B) 100, carried on 14 chromosomes C) 200, carried on 7 chromosomes D) 200, carried on 14 chromosomes
A
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"? A) tree stump B) deceased animal C) fire pit D) cement-capped well
A
Mycorrhizae are to the roots of vascular plants as endophytes are to vascular plants' _____. A) leaf mesophyll B) stem apical meristems C) root apical meristems D) xylem
A
Simard et al. (1997) further hypothesized that if reciprocal transfer did occur, it would be a source-sink relationship driven by photosynthetic rates. That is, if one seedling is in full sun and the other in deep shade, there will be a net movement of carbon from the seedling in full sun to the one in deep shade. If a shade was placed over the birch seedlings and the cedar, and the Douglas fir was left in full sun, what result could Simard and colleagues expect? A) More 13C would be found in the birch than in the Douglas fir. B) More 13C would be found in the Douglas fir than in the birch. C) The most 13C would be found in the cedar. D) The most 14C would be found in the cedar.
A
The Gd mat on the fur of the bats should be expected to consist of _____. A) hyphae B) haustoria C) yeasts D) basidia
A
You observe the gametes of a fungal species under the microscope and realize that they resemble animal sperm. To which of the following group does the fungus belong? A) Chytrids B) Zygomycetes C) Basidiomycota D) Ascomycota
A
Explain the significance of the reduced mitochondria of the microsporidia. (Study Guide: Diversity of Fungi)
A 2006 analysis of DNA sequence data from six genes in nearly 200 fungal species indicates that microsporidia are members of an early-diverging lineage of fungi.
The functional significance of porous septa in certain fungal hyphae is most similar to that represented by which pair of structures in animal cells and plant cells, respectively? A) desmosomes — tonoplasts B) gap junctions — plasmodesmata C) tight junctions — plastids D) centrioles — plastids
B
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? A) karyogamy B) mycelial flagella C) breezes distributing spores D) cytoplasmic streaming in hyphae
D
After cytokinesis occurs in budding yeasts, the daughter cell has a _____. A) similar nucleus and more cytoplasm than the mother cell B) smaller nucleus and less cytoplasm than the mother cell C) larger nucleus and less cytoplasm than the mother cell D) similar nucleus and less cytoplasm than the mother cell
D
Arrange the following in order from largest to smallest, assuming that they all come from the same fungus. 1. basidiocarp 2. basidium 3. basidiospore 4. mycelium 5. gill A) 4 →? 5 → 1→ 2 → 3 B) 5 → 1 → 4 → 2 → 3 C) 5 → 1 → 3 → 2 → 4 D) 4 → 1 → 5 → 2 → 3
D
Chapter 31 Fungi Multiple-Choice Questions 1) Which of the following do all fungi have in common? A) meiosis in basidia B) coenocytic hyphae C) sexual life cycle D) absorption of nutrients E) symbioses with algae
D
Concept 31.1 Skill: Application/Analysis Page 1 5) Which of the following is a characteristic of hyphate fungi (fungi featuring hyphae)? A) They acquire their nutrients by phagocytosis. B) Their body plan is a unicellular sphere. C) Their cell walls consist mainly of cellulose microfibrils. D) They are adapted for rapid directional growth to new food sources. E) They reproduce asexually by a process known as budding.
D
Concept 31.1 Skill: Knowledge/Comprehension 2) The hydrolytic digestion of which of the following should produce monomers that are aminated (i.e., have an amine group attached) molecules of beta-glucose? A) insect exoskeleton B) plant cell walls C) fungal cell walls D) A and C only E) A, B and C
D
Concept 31.1 Skill: Knowledge/Comprehension 8) What do fungi and arthropods have in common? A) Both groups are commonly coenocytic. B) The haploid state is dominant in both groups. C) Both groups are predominantly heterotrophs that ingest their food. D) The protective coats of both groups are made of chitin. E) Both groups have cell walls.
D
Concept 31.2 Skill: Application/Analysis 22) Fungal cells can reproduce asexually by undergoing mitosis followed by cytokinesis. Many fungi can also prepare to reproduce sexually by undergoing A) cytokinesis followed by karyokinesis. B) binary fission followed by cytokinesis. C) plasmolysis followed by karyotyping. D) plasmogamy followed by karyogamy. E) sporogenesis followed by gametogenesis.
D
Concept 31.2 Skill: Application/Analysis 26) Which of the following is characterized by the lack of an observed sexual phase in its membersʹ life cycle? A) Glomeromycota B) Basidiomycota C) Chytridiomycota D) Deuteromycota E) Zygomycota
D
Concept 31.2 Skill: Knowledge/Comprehension 16) In most fungi, karyogamy does not immediately follow plasmogamy, which consequently A) means that sexual reproduction can occur in specialized structures. B) results in multiple diploid nuclei per cell. C) allows fungi to reproduce asexually most of the time. D) results in heterokaryotic or dikaryotic cells. E) is strong support for the claim that fungi are not truly eukaryotic.
D
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 B) periods of drought and presence of filamentous body shape C) predominance in swamps and presence of cellulose in cell walls D) colonization of land and loss of flagellated cells
D
In most fungi, karyogamy does not immediately follow plasmogamy, which consequently _____. A) means that sexual reproduction can occur in specialized structures B) results in multiple diploid nuclei per cell C) allows fungi to reproduce asexually most of the time D) results in heterokaryotic or dikaryotic cells
D
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) zygomycetes B) glomeromycetes C) basidiomycetes D) deuteromycetes
D
The adaptive advantage associated with the filamentous nature of fungal mycelia is primarily related to _____. A) the ability to form haustoria and parasitize other organisms B) the potential to inhabit almost all terrestrial habitats C) the increased probability of contact between different mating types D) an extensive surface area well suited for invasive growth and absorptive nutrition
D
Why are mycorrhizal fungi superior to plants at acquiring mineral nutrition from the soil? A) Hyphae are one hundred to one thousand times larger than plant roots. B) Hyphae have a smaller surface-area-to-volume ratio than do the hairs on a plant root. C) Mycelia are able to grow in the direction of food. D) Fungi secrete extracellular enzymes that can break down large molecules.
D
Which of the following cells or structures are associated with asexual reproduction in fungi? A) ascospores B) basidiospores C) zygosporangia D) conidiophores E) ascocarps (Chapter Questions)
D) conidiophores
Describe the evidence that multicellularity evolved independently in fungi and animals. (Study Guide: Diversity of Fungi)
DNA sequence data also indicate that fungi are more closely related to several groups of single-celled protists than to animals, suggesting that the ancestor of fungi was unicellular. ----One such single-celled group, the nucleariids, consists of amoebae that feed on algae and bacteria. Animals are more closely related to a different group of protists, the choanoflagellates.
Explain how fungi acquire their nutrients. (Study Guide: Introduction to Fungi)
Decomposer fungi break down and absorb nutrients from nonliving organisms. Parasitic fungi absorb nutrients from the cells of living hosts. Mutualistic fungi also absorb nutrients from a host organism, but they reciprocate with functions that benefit their partner in some way.
Concept 31.1 Skill: Knowledge/Comprehension 11) The vegetative (nutritionally active) bodies of most fungi are A) composed of hyphae. B) referred to as a mycelium. C) usually underground. D) A and B only E) A, B, and C
E
Concept 31.2 Skill: Application/Analysis 25) A chemical secreted by a female Bombyx moth helps the male of the species locate her, at which time sexual reproduction may occur. This chemical is most similar in function to which chemicals used by sexually reproducing fungi? A) chitin B) enzymes C) lysergic acids D) aflatoxins E) pheromones
E
Concept 31.2 Skill: Knowledge/Comprehension 18) Which process occurs in fungi and has the opposite effect on a cellʹs chromosome number than does meiosis I? A) mitosis B) plasmogamy C) crossing-over D) binary fission E) karyogamy
E
Concept 31.2 Skill: Knowledge/Comprehension 21) Each of the eight ascospores present at the end of mitosis has the same chromosome number and DNA content (ng) as each of the four cells at the end of meiosis. What must have occurred in each spore between the round of meiosis and the round of mitosis? A) double fertilization B) crossing-over C) nondisjunction D) autopolyploidy E) S phase
E
Concept 31.2 Skill: Knowledge/Comprehension 24) For mycelia described as heterokaryons or as being dikaryotic, which process has already occurred, and which process has not yet occurred? A) germination, plasmogamy B) karyogamy, germination C) meiosis, mitosis D) germination, mitosis E) plasmogamy, genetic recombination
E
The adaptive advantage associated with the filamentous nature of fungal mycelia is primarily related to A) the ability to form haustoria and parasitize other organisms. B) avoiding sexual reproduction until the environment changes. C) the potential to inhabit almost all terrestrial habitats. D) the increased probability of contact between different mating types. E) an extensive surface area well suited for invasive growth and absorptive nutrition. (Chapter Questions)
E) an extensive surface area well suited for invasive growth and absorptive nutrition.
Explain the significance of heterokaryotic stages in fungal life cycles. (Study Guide: Introduction to Fungi)
In some species, heterokaryotic mycelia become mosaics, with different nuclei remaining in separate parts of the same mycelium or mingling and even exchanging chromosomes and genes.
Describe the structure of a lichen. Explain the roles of the fungal component of the lichen. (Study Guide: Ecological Impacts of Fungi)
Lichens are symbiotic associations of millions of photosynthetic microorganisms held in a mass of fungal hyphae The fungal component is commonly an ascomycete, but one glomeromycete and 75 basidiomycete lichens are known. The photosynthetic partners are usually unicellular or filamentous green algae or cyanobacteria.
List the characteristics that distinguish fungi from members of other multicellular kingdoms. (Study Guide: Introduction to Fungi)
Members of the kingdom Fungi are eukaryotes, meaning they have complex cells with a nucleus and organelles. Most are multicellular, with the exception of single-celled yeast.
Explain why glomeromycete fungi are ecologically important. (Study Guide: Diversity of Fungi)
Nearly all glomeromycetes form arbuscular mycorrhize. ----The tips of the hyphae that push into plant root cells branch into tiny treelike structures known as arbuscles. ----Such mutualistic partnerships with glomeromycetes are present in 90% of all plants.
Describe the evidence that suggests that Fungi and Animalia are sister kingdoms (Study Guide: Diversity of Fungi)
Phylogenetic systematics suggests that fungi evolved from a unicellular, flagellated protist. DNA sequence data indicate that fungi, animals, and their protist relatives form a clade called opisthokonts, a name that refers to the posterior (opistho-) location of the flagellum.
Describe the processes of plasmogamy and karyogamy in fungi. (Study Guide: Introduction to Fungi)
Plasmogamy is the union of the cytoplasm of the two parent mycelia. Stage in the sexual reproduction of fungi, in which the cytoplasm of two parent cells (usually from the mycelia) fuses together without the fusion of nuclei, effectively bringing two haploid nuclei close together in the same cell. Karyogamy is the the fusion of haploid nuclei contributed by two parents, occurs well after plasmogamy, the cytoplasmic fusion of cells from the two parents. Sexual reproduction in the fungi consists of three sequential stages: plasmogamy, karyogamy, and meiosis. The diploid chromosomes are pulled apart into two daughter cells, each containing a single set of chromosomes (a haploid state). Plasmogamy, the fusion of two protoplasts (the contents of the two cells), brings together two compatible haploid nuclei. At this point, two nuclear types are present in the same cell, but the nuclei have not yet fused. Karyogamy results in the fusion of these haploid nuclei and the formation of a diploid nucleus (i.e., a nucleus containing two sets of chromosomes, one from each parent). The cell formed by karyogamy is called the zygote. In most fungi the zygote is the only cell in the entire life cycle that is diploid. The dikaryotic state that results from plasmogamy is often a prominent condition in fungi and may be prolonged over several generations. In the lower fungi, karyogamy usually follows plasmogamy almost immediately. In the more evolved fungi, however, karyogamy is separated from plasmogamy. Once karyogamy has occurred, meiosis (cell division that reduces the chromosome number to one set per cell) generally follows and restores the haploid phase. The haploid nuclei that result from meiosis are generally incorporated in spores called meiospores. Fungi employ a variety of methods to bring together two compatible haploid nuclei (plasmogamy). Some produce specialized sex cells (gametes) that are released from differentiated sex organs called gametangia. In other fungi two gametangia come in contact, and nuclei pass from the male gametangium into the female, thus assuming the function of gametes. In still other fungi the gametangia themselves may fuse in order to bring their nuclei together. Finally, some of the most advanced fungi produce no gametangia at all; the somatic (vegetative) hyphae take over the sexual function, come in contact, fuse, and exchange nuclei.
Explain how lichens may act as pioneers on newly burned soil or volcanic rock. (Study Guide: Ecological Impacts of Fungi)
The lichen acids penetrate the outer crystals of rocks and help break down the rock. ----This breakdown allows the trapping of soil and starts the process of succession.
Describe the basic body plan of a fungus. (Study Guide: Introduction to Fungi)
The vegetative bodies of multicellular fungi are constructed of tiny filaments called hyphae that form an interwoven mat called a mycelium that infiltrates the material on which the fungus feeds. Fungal hyphae have cell walls built mainly of chitin, a strong but flexible nitrogen-containing polysaccharide identical to that found in arthropods. Most fungi are multicellular with hyphae divided into cells by cross walls, or septa. Coenocytic fungi that lack septa consist of a continuous cytoplasmic mass with hundreds or thousands of nuclei. Some parasitic fungi have specialized hyphae called haustoria, nutrient-absorbing hyphal tips that penetrate the tissues of their host.
Distinguish among the Zygomycota, Ascomycota, and Basidiomycota. Include a description of the sexual structure that characterizes each group and list some common examples of each group. (Study Guide: Diversity of Fungi)
-Zygomycota: Zygotes fungi can form zygosporangia (the organ of the fungi that produce zygotes) that can withstand tremendous environments and one reason is because they are so small. Some could actually be just one cell big. They reproduce using another organ called sporangium, which releases hundreds to thousands of spores (which are haploid (n)). i.e. Pilobolus. -Ascomycota (sac fungi) form sac like structures called asci, which shoot out spores. Then itgerminates in nutrient rich environments. The asci are forms larger structures called the ascocarp, which resembles a bud. i.e. Pezizomycotina -Basidiomycota (club fungi) form mushroom reproductive fruiting bodies. They can also produce puffballs that can emit trillions of spores. i.e. Mushrooms and puffballs
Describe three commercial roles played by fungi. (Study Guide: Ecological Impacts of Fungi)
1. Most people eat mushrooms, the fruiting bodies (basidiocarps) of subterranean fungi. 2. Yeasts are very important in food production. Humans have used yeasts to produce alcoholic beverages and make bread rise for thousands of years. 3. Contributing to medicine, some fungi produce antibiotics used to treat bacterial diseases.
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) the hypothesis that a toxin secreted by Jl cells kills Bd cells when both are present together on frog skin B) the hypothesis that Jl cells infect and kill Bd cells when both are present together on frog skin C) the hypothesis that Jl outcompetes Bd when both are present together on a frog's skin D) the hypothesis that the presence of Jl on frog skin causes a skin reaction that prevents attachment by Bd cells
A
Arrange the following in order from largest to smallest. 1. ascospore 2. ascocarp 3. ascomycete 4. ascus A) 3 → 2 → 4 → 1 B) 3 → 4 → 1 → 2 C) 2 → 3 → 4 → 1 D) 2 → 4 → 1 → 3
A
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 should be true 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 be transcriptionally less active. C) It should have reduced motility. D) It should have a smaller nucleus.
A
Based on graphs (e) and (f) in the figure above, 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.
A
Based on the idea that fungi have pores between their cell walls, which allow cytoplasm to move from one end of the mycelium to the other, which of the following hypotheses is the most plausible? A) If a single mycorrhizal fungus formed symbiotic associations with more than one tree, carbon could travel from one plant to another. B) Parasitic fungi steal nutrients from their hosts. 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) 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.
A
Concept 31.1 Skill: Application/Analysis 7) What is the primary role of a mushroomʹs underground mycelium? A) absorbing nutrients B) anchoring C) sexual reproduction D) asexual reproduction E) protection
A
Concept 31.1 Skill: Knowledge/Comprehension Page 2 10) What accounts most directly for the extremely fast growth of a fungal mycelium? A) rapid distribution of synthesized proteins by cytoplasmic streaming B) a long tubular body shape C) the readily available nutrients from their ingestive mode of nutrition D) a dikaryotic condition that supplies greater amounts of proteins and nutrients
A
Concept 31.1 Skill: Knowledge/Comprehension Page 3 15) Which of the following vary tremendously from each other in morphology and belong to several fungal phyla? A) lichens B) ascomycetes C) club fungi D) arbuscular mycorrhizae E) ergot fungi
A
Concept 31.2 Skill: Application/Analysis 20) What is the ploidy of a single mature ascospore? A) monoploid B) diploid C) triploid D) tetraploid E) polyploid
A
Concept 31.2 Skill: Knowledge/Comprehension 27) A biologist is trying to classify a newly discovered fungus on the basis of the following characteristics: filamentous appearance, reproduction by asexual spores, no apparent sexual phase, and parasitism of woody plants. If asked for advice, to which group would you assign this new species? A) Deuteromycota B) Zygomycota C) Ascomycota D) Basidiomycota E) Glomeromycota
A
Concept 31.2 Skill: Knowledge/Comprehension Page 4 Please refer to the following information to answer the following questions. 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. 19) 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? A) 100, 7 B) 100, 14 C) 200, 7 D) 200, 14 E) 400, 14
A
Fungi have an extremely high surface-area-to-volume ratio. What is the advantage of this to an organism that gets most of its nutrition through absorption? A) The larger surface area allows for more material to be 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 creates more room inside the cells for additional organelles involved in absorption. D) This high ratio means that fungi have a thick, fleshy structure that allows the fungi to store more of the food it absorbs.
A OR B if below --- 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 lower volume prevents the cells from drying out too quickly, which can interfere with absorption. B)The high ratio allows for more material to be acquired from the surroundings and transported through the cell membrane. C)This high ratio creates more room inside the cells for additional organelles involved in absorption. D)This high ratio means that fungi have a thick, fleshy structure that allows the fungi to store more of the food it absorbs.
Among the organisms listed here, which are thought to be the closest relatives of fungi? A) animals B) vascular plants C) mosses D) brown algae E) slime molds (Chapter Questions)
A) animals
Describe the role of fungi as agricultural pests. (Study Guide: Ecological Impacts of Fungi)
About 30% of the 100,000 known species of fungi are pathogens or parasites, mostly of plants.
Describe an animal-fungi mutualistic symbiosis. (Study Guide: Ecological Impacts of Fungi)
Anaerobic chytrids that live in the digestive tracts of sheep and cattle help break down plant matter.
Describe the life cycle of the bread mold, Neurospora crassa. Explain how this organism has played an important role in biological research. (Study Guide: Diversity of Fungi)
Ascomycetes reproduce asexually by producing enormous numbers of asexual spores called conidia. ----Conidia develop in long chains or clusters at the tips of specialized hyphae called conidiophores. Once released, they are dispersed by the wind. In Neurospora, conidia may also be involved in sexual reproduction, fusing with hyphae from a mycelium of a different mating type. In the 1930s, biologists used Neurospora to formulate the one gene-one enzyme hypothesis.
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 flagella C) by cilia D) by hyphae
B
Basidiomycetes are the only fungal group capable of synthesizing lignin peroxidase. What advantage does this group of fungi have over other fungi because of this capability? A) This is always the first group of fungi to begin any kind of plant decomposition. B) This fungal group can break down the tough lignin, which cannot be harnessed for energy, to get to the more useful cellulose. C) This is the only group of fungi that can use lignin for adenosine triphosphate (ATP) production. D) This enzyme releases heat energy from the breakdown of lignin that is used to kill off competing fungi.
B
Concept 31.1 Skill: Knowledge/Comprehension 12) Both fungus-farming ants and their fungi can synthesize the same structural polysaccharide from the beta-glucose. What is this polysaccharide? A) amylopectin B) chitin C) cellulose D) lignin E) glycogen
B
Concept 31.1 Skill: Knowledge/Comprehension 6) The functional significance of porous septa in certain fungal hyphae is most similar to that represented by which pair of structures in animal cells and plant cells, respectively? A) desmosomes : tonoplasts B) gap junctions : plasmodesmata C) tight junctions : plastids D) centrioles : plastids E) flagella : central vacuoles
B
Concept 31.1 Skill: Knowledge/Comprehension 9) In septate fungi, what structures allow cytoplasmic streaming to distribute needed nutrients, synthesized compounds, and organelles throughout the hyphae? A) multiple chitinous layers in cross walls B) pores in cross walls C) complex microtubular cytoskeletons D) two nuclei E) tight junctions that form in cross walls between cells
B
Concept 31.2 Skill: Application/Analysis 17) If all of their nuclei are equally active transcriptionally then, in terms of the gene products they can make, the cells of both dikaryotic and heterokaryotic fungi are essentially A) haploid. B) diploid. C) alloploid. D) completely homozygous. E) completely hemizygous.
B
Deuteromycetes _____. A) represent the phylum in which all the fungal components of lichens are classified B) are the group of fungi that have, at present, no known sexual stage C) are the group that includes molds, yeasts, and lichens D) include the imperfect fungi that lack hyphae
B
Humans have immune systems in which lymph nodes are important, because many 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 hyphae secrete antibiotics, which increases the ability of the infected human to tolerate the fungus. B) Their conversion from yeast to hyphal morphology allows such fast growth that the body's defenses are at least temporarily overwhelmed. C) Defensive cells of humans cannot detect foreign cells that are covered with cell walls composed of cellulose. D) Given that most fungal pathogens attack plants, human defenses are simply not adapted to seek out and destroy fungi.
B
If Bd cannot grow properly at temperatures above 28°C (82°F), then, assuming the amphibians can survive, in which time or place should the chytrid infection proceed most rapidly? 1. cooler months 2. warmer months 3. lower altitudes 4. higher altitudes A) 1 or 3 B) 1 or 4 C) 2 or 3 D) 2 or 4
B
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 _____. A) algae and cyanobacteria are autotrophic B) lichens are not purely mutualistic relationships C) algae require maximal contact with the fungal partner in order to grow at optimal rates D) soredia are asexual reproductive structures combining both the fungal and photosynthetic partners
B
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) Radioactively labeled sugars produced by plants eventually show up in the fungi with which they are associated. 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. D) Radioactive labeling experiments show that plants pass crucial raw materials to the fungus for manufacturing sugars.
B
Plasmogamy can directly result in which of the following? 1. cells with a single haploid nucleus 2. heterokaryotic cells 3. dikaryotic cells 4. cells with two diploid nuclei A) 1 or 3 B) 2 or 3 C) 2 or 4 D) 3 or 4
B
The answer to which of these questions would be of most assistance to one who is attempting to assign the genus Sporothrix to the correct fungal phylum? A) Do these yeasts perform fermentation while growing on the rose-bush thorns, or do they wait until inside a human host? B) Does S. schenkii rely on animal infection to complete some part of its life cycle, or is the infection merely opportunistic? C) Are the hyphae in lymphatic vessels septate, or are they coenocytic? D) Is S. schenkii best described as a decomposer, parasite, pathogen, or mutualist of humans?
B
The microsporidian 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 how many of the following statements should be true? 1. Brachiola should kill the mosquitoes before the malarial parasite they carry reaches maturity. 2. The microsporidian should not be harmful to other insects. 3. Microsporidians should infect mosquito larvae, rather than mosquito adults. 4. The subsequent decline in anopheline mosquitoes should not significantly disrupt human food resources or other food webs. 5. Brachiola must be harmful to male mosquitoes, but not to female mosquitoes. A) 2 and 5 B) 1, 2, and 4 C) 2, 3, 5 D) 3 and 4
B
The multicellular condition of animals and fungi seems to have arisen _____. A) due to common ancestry B) by convergent evolution C) by inheritance of acquired traits D) by serial endosymbioses
B
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 is unaffected by AMF diversity. C) Bromus erectus does not form mycorrhizal associations. D) Bromus erectus produces very little biomass regardless of AMF.
B
When a mycelium infiltrates an unexploited source of dead organic matter, what are most likely to appear within the food source soon thereafter? A) fungal haustoria B) fungal enzymes C) increased oxygen levels D) larger bacterial populations
B
Some fungal species can kill herbivores while feeding off of sugars from its plant host. What type of relationship does this fungus have with its host? A) parasitic B) mutualistic C) commensal D) predatory
B OR A 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? Amutualistic Bcommensal Cparasitic D predatory
All fungi are A) symbiotic B) heterotrophic C) flagellated D) decomposers (Chapter Questions)
B) heterotrophic
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) basidiospores B) spores of ectomycorrhizae C) soredia D) yeasts
C
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) fertilization B) karyogamy C) plasmogamy D) germination
C
Concept 31.1 Skill: Application/Analysis 13) Consider two hyphae having equal dimensions: one from a septate species and the other from a coenocytic species. Compared with the septate species, the coenocytic species should have A) fewer nuclei. B) more pores. C) less chitin. D) less cytoplasm. E) reduced cytoplasmic streaming.
C
Concept 31.1 Skill: Application/Analysis 14) Which of the following terms is correctly associated with fungi in general? A) sporophytes B) make only sexually produced spores C) ecologically important D) polyphyletic E) ingestive nutrition
C
Concept 31.1 Skill: Application/Analysis 4) When a mycelium infiltrates an unexploited source of dead organic matter, what are most likely to appear within the food source soon thereafter? A) fungal haustoria B) soredia C) fungal enzymes D) increased oxygen levels E) larger bacterial populations
C
Concept 31.1 Skill: Knowledge/Comprehension 3) 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? A) plants B) protists C) prokaryotes D) animals E) mutualistic fungi
C
Concept 31.2 Skill: Knowledge/Comprehension Page 5 23) Which of the following statements is true of deuteromycetes? A) They are the second of five fungal phyla to have evolved. B) They represent the phylum in which all the fungal components of lichens are classified. C) They are the group of fungi that have, at present, no known sexual stage. D) They are the group that includes molds, yeasts, and lichens. E) They include the imperfect fungi that lack hyphae.
C
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? A) flowering plants B) protists C) prokaryotes D) grasses
C
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 C) by providing the embryos with some of the organic nutrients they have absorbed D) by strengthening the seed coat that surrounds each seed
C
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 two of these are conclusions make sense on the basis of this information? 1. S. schenkii produces asexual spores within lymph nodes. 2. S. schenkii should be reclassified. 3. S. schenkii continues to have no known sexual stage. 4. The hyphae growing in lymphatic vessels probably belonged to a different fungal species. 5. S. schenkii yeasts belonging to two different mating strains were introduced by the same thorn prick. A) 1 and 3 B) 1 and 5 C) 2 and 5 D) 4 and 5
C
What do fungi and arthropods have in common? A) The haploid state is dominant in both groups. B) Both groups are predominantly autotrophs that produce their own food. C) Both groups use chitin for support. D) Both groups have cell walls.
C
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? A) Inoculate uninfected amphibians with Jl, and determine whether the amphibians continue to remain uninfected by chytrids. B) Inoculate infected amphibians with Jl, and determine whether the amphibians recover from infection by chytrids. C) Take infected amphibians and assign them to two populations. Leave one population alone; inoculate the other with Jl. Measure the rate at which infection proceeds in both populations. D) Take infected amphibians and assign them to two populations. Inoculate one population with a high dose of Jl; inoculate the other with a low dose of Jl. Measure the survival frequency in both populations.
C
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) fungicide might also kill the native yeasts residing on the surfaces of the grapes B) lichens growing on the vines' branches are not harmed C) fungicide might also kill mycorrhizae D) sheeting is transparent so that photosynthesis can continue
C
Which feature seen in chytrids supports the hypothesis that they diverged earliest in fungal evolution? A) the absence of chitin within the cell wall B) coenocytic hyphae C) flagellated spores D) parasitic lifestyle
C
Which of the following best describes the physical relationship of the partners involved in lichens? A) Fungal cells are enclosed within algal cells. B) Lichen cells are enclosed within fungal cells. C) Photosynthetic cells are surrounded by fungal hyphae. D) The fungi grow on rocks and trees and are covered by algae.
C
Which of the following has the LEAST affiliation with all of the others? A) Glomeromycota B) mycorrhizae C) lichens D) arbuscules
C
Why does total biomass (graph e in the figure above) not vary with AMF diversity? A) Plant growth is unaffected by fungal diversity. B) Most of the plants in this system do not form mycorrhizal associations. C) Bromus erectus is the dominant plant species. D) Lotus corniculatus is a rare species.
C
Explain the possible significance of the flagellated spores of chytrid fungi. (Study Guide: Diversity of Fungi)
Chytrids are unique among fungi in having flagellated spores, called zoospores. Molecular evidence supports the hypothesis that chytrids diverged early in fungal evolution.
Distinguish between ectomycorrhizal fungi and arbuscular mycorrhizal fungi. (Study Guide: Introduction to Fungi)
Ectomycorrhizal fungi form sheaths of hyphae over the surface of the plant root and grow into the extracellular spaces of the root cortex. Arbuscular mycorrhizal fungi extend their branching hyphae through the root cell wall and into tubes formed by invagination of the root cell membrane.
Describe some of the roles of fungi in ecosystems. (Study Guide: Ecological Impacts of Fungi)
Fungi are important decomposers of organic material, including the cellulose and lignin of plant cell walls. Fungi form symbiotic relationships with plants, algae, cyanobacteria, and animals.
Define mycosis, and describe some human mycoses. (Study Guide: Ecological Impacts of Fungi)
General term for a fungal infection. 1. Coccidiodomycosis is a systemic mycosis that produces tuberculosis-like symptoms in the lungs. 2. Candida albicans is a normal inhabitant of moist epithelia such as human vaginal lining, but it can become an opportunistic pathogen, leading to so-called "yeast infections."
Describe the life cycle of the black bread mold, Rhizopus stolonifer. (Study Guide: Diversity of Fungi)
The hyphae are coenocytic, with septa found only where reproductive cells are formed. ----Horizontal hyphae spread out over food, penetrate it, and digest nutrients. In the asexual phase, hundreds of haploid spores develop in sporangia at the tips of upright hyphae. ----Within each sporangium, hundreds of haploid spores develop and are dispersed through the air. ----Spores that happen to land on moist food germinate, growing into new mycelia. Plasmogamy of opposite mating types produces a zygosporangium within which karyogamy and then meiosis occur. Although the zygosporangium represents the zygote (2n) stage in the life cycle, it is not a zygote in the sense of a cell with one diploid nucleus. Zygosporangia are resistant to freezing and drying and are metabolically inactive. ----When conditions improve, a zygosporangium undergoes meiosis, germinates into a sporangium, and releases genetically diverse haploid spores that colonize new substrates.