Exam 31: Fungi

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

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?

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?

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

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?

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

Which of the following is a characteristic of hyphate fungi (fungi featuring hyphae)?

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?

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?

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?

In most fungi,karyogamy does not immediately follow plasmogamy,which consequently

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?

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

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

The multicellular condition of animals and fungi seems to have arisen

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 southern Canada.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 2007,it is estimated that up to one million bats have perished from WNS. The Gd mat on the fur of the bats should be expected to consist of ________.

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

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?

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

The fact that infection by Bd causes lethargy in many infected amphibians can have what effect on efforts to accurately census the numbers of dead or dying amphibians at a particular time,in a particular habitat?