Ch 31
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
B) haustoria
C) yeasts
D) basidia
A
2) 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
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?
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 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
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?
A)
flowering plants
B) protists
C) prokaryotes
D) grasses
C
10) 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
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?
A) karyogamy
B) mycelial flagella
C) breezes distributing spores
D)
cytoplasmic streaming in hyphae
D
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 ________.
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
13) 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
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?
A) parasitic
B) mutualistic
C) commensal
D) predatory
B
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
B) increased production of corn ears in
plants with mycorrhizae than in plants without mycorrhizae
C)
increased need for fertilizer in plants with mycorrhizae than in
plants without mycorrhizae
D) increased mortality in plants with mycorrhizae than in plants without mycorrhizae
B
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?
B) Do nitrogen-fixing
bacteria provide nitrogen to the fungi?
C) What is the
evolutionarily oldest method of trapping nematodes?
D) What mechanisms do nematodes have that could allow them to escape from Arthrobotrys?
A
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?
A) fertilization
B) karyogamy
C) plasmogamy
D) germination
C
26) 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
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?
A) zygomycetes
B) glomeromycetes
C) basidiomycetes
D) deuteromycetes
D
28) Plasmogamy can directly result in which of the following?
A) cells with a single haploid nucleus or dikaryotic cells
B)
heterokaryotic cells or dikaryotic cells
C) heterokaryotic cells
or cells with two diploid nuclei
D) dikaryotic cells or cells with two diploid nuclei
B
29) 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
30) 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
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?
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
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.
B) The
ascomycete should kill the mosquitoes before the malarial parasite
they carry reaches maturity and should not be harmful to other
insects.
C) The ascomycete should not be harmful to other insects
and should infect mosquito larvae, rather than mosquito
adults.
D) The ascomycete should infect mosquito larvae, rather
than mosquito adults, and the subsequent decline in anopheline
mosquitoes should not significantly disrupt human food resources.
B
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.
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
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
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
35) 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
36) 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
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 ________.
A) secondary endoparasitism
B) horizontal gene transfer
C) paraphyletic evolution
D) convergent evolution
D
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
C) fossils that show hyphae wrapped around
seeds
D) 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
B
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.
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
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?
A) chytrids
B) zygomycetes
C) Basidiomycota
D) Ascomycota
A
41) Arrange the following in order from largest to smallest.
A) ascomycete, ascocarp, ascus, ascospore
B) ascomycete, ascus,
ascospore, ascocarp
C) ascocarp, ascomycete, ascus, ascospore
D) ascocarp, ascus, ascospore, ascomycete
A
42) Arrange the following in order from largest to smallest, assuming
that they all come from the same fungus.
A) mycelium, gill,
basidiocarp, basidium, basidiospore
B) gill, basidiocarp,
mycelium, basidium, basidiospore
C) gill, basidiocarp, basidiospore, basidium, mycelium
D) mycelium, basidiocarp, gill, basidium, basidiospore
D
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?
A) by wind-blown spores
B) by flagella
C) by cilia
D) by hyphae
B
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?
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
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.
B) Jl cells infect and kill Bd cells when
both are present together on frog skin.
C) Jl outcompetes Bd when
both are present together on a frog's skin.
D) The presence of Jl
on frog skin causes a skin reaction that prevents attachment by Bd cells.
A
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?
A) 100 ng on 7
chromosomes
B) 100 ng on 14 chromosomes
C) 200 ng on 7
chromosomes
D) 200 ng on 14 chromosomes
A
53) Which of the following characteristics would be most helpful in
distinguishing among different species of fungi?
A)
morphology
B) hyphae structure
C) DNA sequence
D) life cycle
C
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?
A) The organism saves energy during
cell division because fewer DNA bases must be duplicated.
B) It
is more difficult for viruses to insert themselves into a compact
genome.
C) There is less genetic variation that can lead to
mutation.
D) The spores will be small and thus travel a greater distance.
A
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?
A) The
hyphae secrete antibiotics, which increases the ability of the
infected human to tolerate the fungus.
B) The fungal 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
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 ________.
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
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?
A) basidiospores
B) spores of ectomycorrhizae
C) soredia
D) yeasts
C
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
C) by
providing the embryos with some of the organic nutrients the fungi
have absorbed
D) by strengthening the seed coat that surrounds each seed
C
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.
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 should be reclassified; S. schenkii yeasts
belonging to two different mating strains were introduced by the same
thorn prick.
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.
C
66) 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) Fungi grow on rocks and trees and are covered by algae.
C
67) 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
68) Fungi interact with many organisms in mutualistic ways. Which of
the following involves a fungus that is mutualistic with another
organism?
A) a fungus and a protozoan that live together as a
lichen
B) a fungus that is raised by ants on leaves that the ants
collect from trees and shrubs
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
B
69) Fungi produce many compounds that humans are able to use
medically. How can you account for these compounds?
A) Humans
used artificial selection to develop fungi that produced specific
compounds.
B) The presence of the compounds in the fungi were
accidentally produced and have no function.
C) The compounds probably provide a benefit to the fungi.
D) The compounds are produced as a result of sexual reproduction and recombination.
C
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.
B) Truffles
produce an odor that mammals can detect and find attractive.
C)
Truffles probably produce toxins that can harm the mammals that eat them.
D) Truffle fruiting bodies are important in decomposition of wood.
B
71) If you wanted to use fungi to improve the environment, which of
the following research goals would make the most sense?
A)
Discover the lignin-digesting enzymes of fungi, and use them to digest
plant tissues left over from food-crop residues and produce a
biofuel.
B) 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.
C) Discover the enzymes that
fungi use to break down plant matter and use them to increase
decomposition rates in order to slow global warming.
D) Develop a
strain of fungus that produces enzymes that absorb oxygen and will
help slow global warming.
A
1) All fungi are
A) symbiotic.
B) heterotrophic.
C)
flagellated.
D) decomposers.
B
2) Which of the following cells or structures are associated with asexual reproduction in fungi?
A) ascospores
B) basidiospores
C) zygosporangia
D) conidiophores
D
3) The closest relatives of fungi are thought to be the
A) animals.
B) vascular plants.
C) mosses.
D) slime molds.
A
4) The most important adaptive advantage associated with the
filamentous nature of fungal mycelia is
A) the ability to form
haustoria and parasitize other organisms.
B) the potential to
inhabit almost all terrestrial habitats.
C) the increased chance of contact between mating types.
D) an
extensive surface area well suited for invasive growth and absorptive nutrition.
D