Chapter 31 Practice

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

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

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

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

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) if a single mychorrhizal fungus formed symbiotic associations w/ more than one tree, carbon could travel from one plant to another

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) leaf mesophyll mycorrhizae - roots endophytes - leaf mesophyll

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

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

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

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

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) deuteromycetes are the group of fungi that have no known sexual stage

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) gap junctions - plasmodesmata

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

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

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) plasmogamy

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) prokaryotes

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

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

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) cytoplasmic streaming in hyphae

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) fungi secrete extracellular enzymes that can break down large molecules

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_ colonization of land and loss of flagellated cells