Exam 31: Fungi

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

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

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

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. -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

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

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

Which of the following statements is true of deuteromycetes?

Fungi differ from other heterotrophic organisms in which way?

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

When adult amphibian skin harbours populations of the bacterium, Janthinobacterium lividum (Jl), chytrid infection seems to be inhibited. Which of the following represents the best experimental design for conclusively determining whether this inhibition is real?

The photosynthetic symbiont of a lichen is often

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?

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?

The following questions refer to the description below. A lichen is a mutualistic association between a fungus and a green algae or cyanobacteria. There are clear morphological differences in lichen body form; some have flat bodies and are very close together, others have leaf-like bodies, and still others grow upright. The association between the two organisms is so complete that lichens are classified as a single organism. -Lichens are found in a wide variety of habitats, including rocks, soil, tree bark, buildings, etc. Aging of lichens has shown that some are thousands of years old; how is this possible when you see that some of these lichens are very small?

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?

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.

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 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?

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

Use the following information to answer the questions below. Rose-picker's disease is caused by the yeast, Sporothrix 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. -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?