Exam 31: Fungi

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

When a mycelium infiltrates an unexploited source of dead organic matter,what are most likely to appear within the food source soon thereafter?

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

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?

The vegetative (nutritionally active)bodies of most fungi are

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

When a mycelium infiltrates an unexploited source of dead organic matter,what are most likely to appear within the food source soon thereafter?

Which of the following best describes the physical relationship of the partners involved in lichens?

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?

Which feature seen in chytrids supports the hypothesis that they diverged earliest in fungal evolution?

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?

Which of the following statements is true of deuteromycetes?

Why are mycorrhizal fungi superior to plants at acquiring mineral nutrition from the soil?

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?

In septate fungi,what structures allow cytoplasmic streaming to distribute needed nutrients,synthesized compounds,and organelles throughout the hyphae?

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. -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?

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?

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

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?

What makes it risky to rely on the presence of chitin in adult amphibian skin as the sole positive test for the presence of chytrids?