Deck 31: Fungi

Question 1

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

Answer 1

C

Question 2

Fungi differ from other heterotrophic organisms in which way?

A)They make their own food if they cannot obtain sufficient food by ingestion.
B)They ingest only microscopic organisms.
C)They secrete enzymes on the outside of a food source, and then absorb nutrients from both living and non-living cells.
D)They have only a few very specific yet weak enzymes for digestion.
E)Their enzymes can break down only simple molecules.

Answer 2

C

Question 3

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

Answer 3

A

Question 4

The hydrolytic digestion of which of the following should produce monomers that are aminated (i.e., have an amine group attached)molecules of β-glucose?

A)insect exoskeleton
B)plant cell walls
C)fungal cell walls
D)Three of these responses are correct.
E)Two of these responses are correct.

Question 5

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.

Question 6

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

Question 7

Immediately after karyogamy occurs, which term applies?

A)plasmogamy
B)heterokaryotic
C)dikaryotic
D)diploid

Question 8

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.

Question 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

Question 10

Both fungus-farming ants and their fungi can synthesize the same structural polysaccharide from the β-glucose. What is this polysaccharide?

A)amylopectin
B)chitin
C)cellulose
D)lignin
E)glycogen

Question 11

Which description does not apply equally well to both sexual and asexual spores?

A)have haploid nuclei
B)represent the dispersal stage
C)are produced by meiosis
D)upon germination, will subsequently undergo S phase and mitosis

Question 12

The following statements about mycorrizhae are true, with the exception of

A)almost all vascular plants have mycorrhizae.
B)nutrients are transferred between different trees by mycorrhizae.
C)in reforestation, seedlings are innoculated with mycorrhizae to enhance their growth.
D)arbuscular mycorrhizae is parasitic on some species of plants.

Question 13

After cytokinesis occurs in budding yeasts, the daughter cell has a

A)smaller 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.

Question 14

What is the importance of a high surface area to volume ratio of mycelia?

A)allows for efficient absorption of nutrients
B)protection from freezing
C)new hyphae are constantly replacing dead hyphae
D)hyphae need to be long to reach different plant roots that are far apart
E)mycelia cannot survive in confined spaces

Question 15

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 2
B)1 or 3
C)2 or 3
D)2 or 4
E)3 or 4

Question 16

The vegetative (nutritionally active)bodies of most fungi are

A)composed of hyphae.
B)referred to as a mycelium.
C)usually underground.
D)Three of these responses are correct.
E)Two of these responses are correct.

Question 17

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.

Question 18

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.

Question 19

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

Question 20

Do cell walls of fungi differ from cell walls of plants?

A)Yes; cell walls of fungi contain chitin, cell walls of plants contain cellulose.
B)No; cell walls of fungi and plants contain chitin.
C)No; cell walls of fungi and plants contain cellulose.
D)Yes; cell walls of fungi contain peptidoglycan, cell walls of plants contain cellulose.
E)Yes; cell walls of fungi contain lignin, cell walls of plants contain cellulose.

Question 21

Among sac fungi, which of these correctly distinguishes ascospores from conidia?

A)Ascospores are diploid, whereas conidia are haploid.
B)Ascospores are produced only by meiosis, whereas conidia are produced only by mitosis.
C)Ascospores have undergone genetic recombination during their production, whereas conidia have not.
D)Ascospores are larger, whereas conidia are smaller.
E)Ascospores will germinate into haploid hyphae, whereas conidia will germinate into diploid hyphae.

Question 22

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 moulds, yeasts, and lichens.
E)They include the imperfect fungi that lack hyphae.

Question 23

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 natural means, and is a homology.
E)by serial endosymbioses.

Question 24

The microsporidian, Brachiola gambiae, parasitizes the mosquito, Anopheles gambiae. Adult female mosquitoes must take blood meals in order 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)one statement only
B)two statements
C)three statements
D)four statements
E)all five statements

Question 25

Which process occurs in fungi and has the opposite effect on a cell's chromosome number than does meiosis I?

A)mitosis
B)plasmogamy
C)crossing over
D)binary fission
E)karyogamy

Question 26

Many infected animals are induced by the parasitic microsporidians to develop huge cells, known as xenomas, which are full of spores. Given their large size, what should be true of the xenomas?

A)The parasite must endow the xenoma with some way to overcome its unfavourable surface area-to-volume ratio.
B)The xenoma must obtain mitochondria to survive.
C)The xenoma must gain a cell wall; otherwise, it will lyse.
D)The xenoma acts as a prison, of sorts, to keep the spores from escaping and infecting other organisms.

Question 27

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)alternation of generations
D)breezes distributing spores
E)cytoplasmic streaming in hyphae

Question 28

Chemicals, secreted by soil fungi, that inhibit the growth of bacteria are known as

A)antibodies.
B)aflatoxins.
C)hallucinogens.
D)antigens.
E)antibiotics.

Question 29

Arrange the following from largest to smallest. 1. ascospore
2. ascocarp
3. ascomycete
4. ascus

A)3 → 4 → 2 → 1
B)3 → 2 → 4 → 1
C)3 → 4 → 1 → 2
D)2 → 3 → 4 → 1
E)2 → 4 → 1 → 3

Question 30

If all of their nuclei are equally active transcriptionally, then the cells of both dikaryotic and heterokaryotic fungi, in terms of the gene products they can make, are essentially

A)haploid.
B)diploid.
C)alloploid.
D)completely homozygous.
E)completely hemizygous.

Question 31

Arrange the following 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 → 4 → 3 → 2
D)5 → 1 → 3 → 2 → 4
E)4 → 1 → 5 → 2 → 3

Question 32

What are the sporangia of the bread mould Rhizopus?

A)asexual structures that produce haploid spores
B)asexual structures that produce diploid spores
C)sexual structures that produce haploid spores
D)sexual structures that produce diploid spores

Question 33

Which of the following characteristics is shared by both chytrids and other kinds of fungi?

A)presence of flagella
B)zoospores
C)autotrophic mode of nutrition
D)cell walls of cellulose
E)nucleotide sequences of several genes

Question 34

You are given an organism to identify. It has a fruiting body that contains many structures with eight haploid spores lined up in a row. What kind of a fungus is this?

A)zygomycete
B)ascomycete
C)deuteromycete
D)chytrid
E)basidiomycete

Question 35

In what structures do both Penicillium and Aspergillus produce asexual spores?

A)asci
B)zygosporangia
C)rhizoids
D)gametangia
E)conidiophores

Question 36

Which of the following has the least affiliation with all of the others?

A)Glomeromycota
B)mycorrhizae
C)lichens
D)arbuscules
E)mutualistic fungi

Question 37

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
E)continental drift and mode of spore dispersal

Question 38

Which of these paired fungal structures are structurally and functionally most alike?

A)conidia and basidiocarps
B)sporangia and hyphae
C)soredia and gills
D)haustoria and arbuscules
E)zoospores and mycelia

Question 39

Genetic variation in fungi occurs through

A)karyogamy.
B)meiosis.
C)plasmogamy.
D)budding.
E)A and B.

Question 40

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 produce ribosomal RNA at a slower rate.
C)It should be transcriptionally less active.
D)It should have reduced motility.
E)It should have a smaller nucleus.

Question 41

Both fungus-derived antibiotics and hallucinogens used by humans probably evolved in fungi as a means to

A)reduce competition for nutrients.
B)help humanity survive.
C)promote their ingestion of foodstuffs.
D)eliminate other fungi.
E)discourage animal predators.

Question 42

The next few questions refer to the following phylogenetic trees.

I.

II.

III.

IV.
Which tree depicts the microsporidians as a sister group of the fungi, rather than as a fungus?

A)I
B)II
C)III
D)IV

Question 43

In both lichens and mycorrhizae, what does the fungal partner provide to its photosynthetic partner?

A)carbohydrates
B)fixed nitrogen
C)antibiotics
D)water and minerals
E)protection from harmful UV

Question 44

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations A-D are all 0.5 metres below the soil surface. Responses may be used once, more than once, or not at all.

Which location is nearest to basidiocarps?

A)A
B)B
C)C
D)D

Question 45

The next few questions refer to the following phylogenetic trees.

I.

II.

III.

IV.
Which tree depicts the microsporidians as a sister group of the ascomycetes?

A)I
B)II
C)III
D)IV

Question 46

Which of the following terms refers to symbiotic relationships that involve fungi living between the cells in plant leaves?

A)pathogens
B)endosymbioses
C)endophytes
D)lichens
E)mycorrhizae

Question 47

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations A-D are all 0.5 metres below the soil surface. Responses may be used once, more than once, or not at all.

At which location is the mycelium currently absorbing the most nutrients per unit surface area, per unit time?

A)A
B)B
C)C
D)D

Question 48

If Penicillium typically secretes penicillin without disturbing the lichen relationship in which it is engaged, then what must have been true about its partner?

A)It should have lacked peptidoglycan in its cell wall.
B)It was probably a red alga.
C)It was probably a member of the domain Bacteria.
D)It was probably a heterotrophic prokaryote.
E)It was probably infected by bacteriophage.

Question 49

Sexual reproduction has never been observed among the fungi that produce the blue-green marbling of blue cheeses. What is true of these fungi and others that do not have a sexual stage?

A)They are currently classified among the ascomycetes.
B)They do not form heterokaryons.
C)Their spores are probably produced by mitosis.
D)Three of these responses are correct.
E)Two of these responses are correct.

Question 50

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.
E)Algal cells and fungal cells mix together without any apparent structure.

Question 51

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations A-D are all 0.5 metres below the soil surface. Responses may be used once, more than once, or not at all.

What is the most probable location of the oldest portion of this mycelium?

A)A
B)B
C)C
D)D

Question 52

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)fungi get all of the nutrition they need via the "leakiness" of photosynthetic partners.
E)soredia are asexual reproductive structures combining both the fungal and photosynthetic partners.

Question 53

The next few questions refer to the following phylogenetic trees.

I.

II.

III.

IV.
Which tree depicts the closest relationship between zygomycetes and chytrids?

A)I
B)II
C)III
D)IV

Question 54

Lichens are older than plants. Is it possible that lichens were an important component in aiding the colonization of land by plants?

A)Yes; lichens could have floated in oceans and accidentally been washed up on land.
B)Yes; lichens could have modified the rocks and soil in a similar way that they do today when they colonize areas disturbed by volcanic explosions and fires.
C)No, because fungus and algae colonized land at different times.
D)No, because the fungus component of lichens is not as old as algae.
E)More experiments need to be done before we are sure.

Question 55

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.

Question 56

Lichens are symbiotic associations of fungi and

A)mosses.
B)cyanobacteria.
C)green algae.
D)Three of these responses are correct.
E)Two of these responses are correct.

Question 57

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

Question 58

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.
E)waxy cuticle.

Question 59

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
E)leaves (as food for fungus-farming ants)

Question 60

Which of the following conditions is caused by a fungus that is accidentally consumed along with rye flour?

A)ergotism
B)athlete's foot
C)ringworm
D)candidiasis (Candida yeast infection)
E)coccidioidomycosis

Question 61

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

A)by wind-blown spores
B)by flagella
C)by cilia
D)by pseudopods
E)by hyphae

Question 62

In which of the following human mycoses should one expect to find a growth pattern most similar to that of the mycelium that produced the fairy ring?

A)skin mycoses
B)coccidiomycosis (lung infection)
C)systemic (bloodborne)Candida infection
D)Sporothrix infection of lymphatic vessels
E)Tinea tonsurans infection limited to interior of hair shafts

Question 63

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

A)ascomycetes
B)zygomycetes
C)glomeromycetes
D)basidiomycetes
E)deuteromycetes

Question 64

Use the following information to answer the questions below.
For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection.
Which of the following are protists, the organisms thought to share the closest ancestor with the chytrids?

A)nucleariids
B)choanoflagellates
C)zygomycetes
D)algae
E)diplomonads

Question 65

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations A-D are all 0.5 metres below the soil surface. Responses may be used once, more than once, or not at all.

Assume that all four locations are 0.5 m above the surface. On a breezy day with prevailing winds blowing from left to right, where should one expect to find the highest concentration of free basidiospores in an air sample?

A)A
B)B
C)C
D)D

Question 66

Please refer to the following information to answer the next few 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.
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

Question 67

Surface area represents the area available for exchange with the environment, whereas volume represents the cytoplasm which requires nutrients and from which waste products (usually toxic)must be removed. Which of the following should provide the most favourable conditions for effective exchange?

A)a smaller unicellular yeast
B)a larger unicellular yeast
C)a shorter filamentous hypha
D)a longer filamentous hypha

Question 68

Use the following information to answer the questions below.
For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection.
The chytrid sporangia reside within the amphibian epidermal cells. Consequently, which term(s)apply to Bd? 1. ectosymbionts
2. parasites
3. commensals
4. pathogens
5. endosymbionts

A)1 and 2
B)1 and 3
C)2 and 4
D)2, 3, and 5
E)2, 4, and 5

Question 69

Use the following information to answer the questions below.
For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection.
Sexual reproduction has not been observed in Bd. A Bd sporangium initially contains a single, haploid cell. Which of the following processes must be involved in generating the multiple zoospores eventually produced by each sporangium? 1. S phase
2. cytokinesis
3. mitosis
4. meiosis

A)1 and 2
B)1 and 3
C)2 and 3
D)1, 2, and 3
E)1, 2, and 4

Question 70

Use the following information to answer the questions below.
Unicellular yeasts can be represented as spheres, whereas filamentous hyphae more closely resemble cylinders. As these two geometric figures increase in size, their surface area-to-volume ratios change. The following tables demonstrate how this ratio changes, first for spheres, and second for cylinders. For the cylinder, girth (i.e., radius, r) will remain constant, whereas length, L, will increase. Note the formulas below the respective tables.
A sphere's change in surface area and volume with increasing radius, r

Area of a Sphere = 4r² Volume of a Sphere = 4/3r³
A cylinder's change in surface area and volume with increasing length, L

Area of a Cylinder = 2(r²) + 2rL Volume of a Cylinder = r²ᴸ
As a direct result of increasing surface area in both yeasts and filamentous hyphae, which cell structures/materials must also increase? 1. amount of chitin
2. number of nuclei
3. amount of plasma membrane
4. number of mitochondria
5. amount of peptidoglycan

A)1 only
B)1 and 3
C)2 and 3
D)2 and 4
E)1, 3, and 5

Question 71

Both axes of the graph are linear. Thus, the shape of the line plotted on this graph most accurately depicts the

A)volume of a sphere as the radius, r, increases.
B)surface area of a sphere as the radius, r, increases.
C)volume of a cylinder as length, L, increases.
D)surface area of a cylinder as length, L, increases.

Question 72

Use the following information to answer the questions below.
Recent genetic studies of the structure of microsporidian genomes, as well as the sequences of their tubulin genes and the gene for RNA polymerase II, indicate that microsporidians are closely related to the fungi. Microsporidians lack flagella, centrioles, peroxisomes, and mitochondria (although they do have degenerate mitochondria, called mitosomes). They have the smallest genome of any eukaryote, and it is a genome that changes quickly. The genome is contained within two haploid nuclei. All microsporidians are obligate intracellular parasites. They use a unique organelle called a polar filament to gain access to the cells of their hosts. One species causes chronic diarrhea in AIDS patients. Another parasitizes Anopheles gambiae, the mosquito that transmits a fatal form of malaria to humans.
The lifestyle of microsporidians is most similar to that of

A)scavengers.
B)viruses.
C)free-living yeasts.
D)ectoparasites.

Question 73

Use the following information to answer the questions below.
Recent genetic studies of the structure of microsporidian genomes, as well as the sequences of their tubulin genes and the gene for RNA polymerase II, indicate that microsporidians are closely related to the fungi. Microsporidians lack flagella, centrioles, peroxisomes, and mitochondria (although they do have degenerate mitochondria, called mitosomes). They have the smallest genome of any eukaryote, and it is a genome that changes quickly. The genome is contained within two haploid nuclei. All microsporidians are obligate intracellular parasites. They use a unique organelle called a polar filament to gain access to the cells of their hosts. One species causes chronic diarrhea in AIDS patients. Another parasitizes Anopheles gambiae, the mosquito that transmits a fatal form of malaria to humans.
Which of the following microsporidian features are shared with many other fungi? 1. chitinous cell wall
2. two haploid nuclei per cell
3. polar filament
4. chemoheterotrophy

A)1 and 2
B)1 and 3
C)1 and 4
D)1, 2, and 4
E)2, 3, and 4

Question 74

Use the following information to answer the questions below.
Unicellular yeasts can be represented as spheres, whereas filamentous hyphae more closely resemble cylinders. As these two geometric figures increase in size, their surface area-to-volume ratios change. The following tables demonstrate how this ratio changes, first for spheres, and second for cylinders. For the cylinder, girth (i.e., radius, r) will remain constant, whereas length, L, will increase. Note the formulas below the respective tables.
A sphere's change in surface area and volume with increasing radius, r

Area of a Sphere = 4r² Volume of a Sphere = 4/3r³
A cylinder's change in surface area and volume with increasing length, L

Area of a Cylinder = 2(r²) + 2rL Volume of a Cylinder = r²ᴸ
Which statement is a correct interpretation of the data in the previous tables?

A)As a sphere gets bigger, its surface area and volume increase at about the same pace.
B)As a cylinder gets bigger, its surface area increases at a greater pace than does its volume.
C)As a cylinder gets bigger, its volume increases at about the same pace at which the volume of a sphere increases.
D)As spheres and cylinders get bigger, the surface area of a cylinder increases at a faster pace than does the surface area of a sphere.

Question 75

Please refer to the following information to answer the next few 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.
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
E)400, carried on 14 chromosomes

Question 76

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)septic tank
B)tree stump
C)deceased animal
D)fire pit
E)cement-capped well

Question 77

Use the following information to answer the questions below.
Recent genetic studies of the structure of microsporidian genomes, as well as the sequences of their tubulin genes and the gene for RNA polymerase II, indicate that microsporidians are closely related to the fungi. Microsporidians lack flagella, centrioles, peroxisomes, and mitochondria (although they do have degenerate mitochondria, called mitosomes). They have the smallest genome of any eukaryote, and it is a genome that changes quickly. The genome is contained within two haploid nuclei. All microsporidians are obligate intracellular parasites. They use a unique organelle called a polar filament to gain access to the cells of their hosts. One species causes chronic diarrhea in AIDS patients. Another parasitizes Anopheles gambiae, the mosquito that transmits a fatal form of malaria to humans.
Given the eukaryotic structures they lack, it should be expected that microsporidians also lack

A)the "9 + 2 pattern" of microtubules.
B)chitin.
C)lysosomes.
D)nuclei.
E)centrosomes.

Question 78

The following figure depicts the outline of a large fairy ring that has appeared overnight in an open meadow, as viewed from above. The fairy ring represents the furthest advance of this mycelium through the soil. Locations A-D are all 0.5 metres below the soil surface. Responses may be used once, more than once, or not at all.

At which location should one find the lowest concentration of fungal enzymes, assuming that the enzymes do not diffuse far from their source, and that no other fungi are present in this habitat?

A)A
B)B
C)C
D)D

Question 79

Please refer to the following information to answer the next few 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.
What is the ploidy of a single mature ascospore?

A)monoploid
B)diploid
C)triploid
D)tetraploid
E)polyploid

Question 80

Some fungi can exist either as unicellular yeasts or as filamentous hyphae. Which of these forms would be most favourable in an environment where nutrients are limited?

A)a smaller unicellular yeast
B)a larger unicellular yeast
C)a shorter filamentous hypha
D)a longer filamentous hypha