Fungi

Fungi are __________ organisms.

__________ fungi absorb nutrients from living organisms.

There is a fungus in Oregon that covers 890,965 hectares! The bulk of this fungus is most likely _____.

In fungi, the function of the mycelium is _____.

Fungi that consist of a continuous mass containing hundreds or thousands of nuclei are known as _____.

Parasitic fungi possess hyphae that are modified to penetrate and absorb nutrients from host tissue. Such modified hyphae are called _____.

You can buy mycorrhizal fungus to add to soil when you plant trees and other plants. Why would you want to do this?

The cell walls of fungal cells are composed of _____.

Hyphae with two nuclei per cell are called _____.

Molecular evidence suggests that fungi _____.

Evidence that mycorrhizae, the mutualistic relationship between plants and fungi, existed from the beginning of the colonization of land comes from _____.

What is the major feature of glomeromycetes?

While hiking through a forest, you discover a fungus growing on the remains of a decaying tree trunk. You hypothesize that it is a basidiomycete fungus because it resembles a mushroom in shape and size. If your logic is correct, microscopic analysis of the tissue found in the stalk of this fungus will reveal the presence of _____.

Fungi in the phylum Basidiomycota are the most important decomposers of wood because of their ability to break down _____.

Lichens are _____.

An ascus is _____.

A dramatic example of the pathogenicity of certain fungi is the dramatic decrease of the American chestnut tree by _____.

Two of the most common mycoses (fungal infections) in humans are _____.

All fungi are a. symbiotic. b. heterotrophic. c. flagellated. d. decomposers.

The mycelial growth habit leads to a body with a high surface-area-to-volume ratio. Why is this important? a. Mycelia have a large surface area for absorption. b. The hyphae that make up mycelia are long, thin tubes. c. Most hyphae are broken up into compartments by walls called septa, although some exist as single, gigantic cells. d. Hyphae can infiltrate living or dead tissues.

The mycelial growth habit leads to a body with a high surface-area-to-volume ratio. Why is this important? a. Mycelia have a large surface area for absorption. b. The hyphae that make up mycelia are long, thin tubes. c. Most hyphae are broken up into compartments by walls called septa, although some exist as single, gigantic cells. d. Hyphae can infiltrate living or dead tissues.

Which of the following cells or structures are associated with asexual reproduction in fungi? a. ascospores b. basidiospores c. zygosporangia d. conidiophores

The closest relatives of fungi are thought to be the a. animals. b. vascular plants. c. mosses. d. slime molds.

The hyphae of arbuscular mycorrhizal fungi (AMF) form bushy structures after making contact with the plasma membrane of a root cell. What is the function of these structures? a. They anchor the fungus inside the root, so the association is more permanent. b. They increase the surface area available for the transfer of nutrients. c. They produce toxins that protect the plant cells against herbivores. d. They break down cellulose and lignin in the plant cell wall.

The hyphae of arbuscular mycorrhizal fungi (AMF) form bushy structures after making contact with the plasma membrane of a root cell. What is the function of these structures? a. They anchor the fungus inside the root, so the association is more permanent. b. They increase the surface area available for the transfer of nutrients. c. They produce toxins that protect the plant cells against herbivores. d. They break down cellulose and lignin in the plant cell wall.

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.

What does it mean to say that a hypha is dikaryotic? a. Two nuclei fuse during sexual reproduction to form a zygote. b. Two independent nuclei, derived from different individuals, are present in each cell. c. The nucleus is diploid or polyploid—not haploid. d. It is extremely highly branched, which increases its surface area and thus absorptive capacity.

What does it mean to say that a hypha is dikaryotic? a. Two nuclei fuse during sexual reproduction to form a zygote. b. Two independent nuclei, derived from different individuals, are present in each cell. c. The nucleus is diploid or polyploid—not haploid. d. It is extremely highly branched, which increases its surface area and thus absorptive capacity.

Comparisons of ribosomal RNA among many different modern species indicate that                   . a. there are two very divergent groups of prokaryotes; b. the Protista represents a conglomeration of very unrelated forms; c. fungi are more closely related to animals than to plants; d. A and B are correct; e. A, B, and C are correct

The Greek root ecto means “outer.” Why are ectomycorrhizal fungi, or EMF, aptly named? a. Their hyphae form tree-like branching structures inside plant cell walls. b. They are mutualistic. c. Their hyphae form dense mats that envelop roots but do not penetrate the cell walls. d. They transfer nitrogen from outside their plant hosts to the interior.

The Greek root ecto means “outer.” Why are ectomycorrhizal fungi, or EMF, aptly named? a. Their hyphae form tree-like branching structures inside plant cell walls. b. They are mutualistic. c. Their hyphae form dense mats that envelop roots but do not penetrate the cell walls. d. They transfer nitrogen from outside their plant hosts to the interior.

SCIENTIFIC INQUIRY • INTERPRET THE DATA The grass Dichanthelium lanuginosum lives in hot soils and houses fungi of the genus Curvularia as endophytes. Researchers tested the impact of Curvularia on the heat tolerance of this grass. They grew plants without (E−) and with (E+) Curvularia endophytes at different temperatures and measured plant mass and the number of new shoots the plants produced. Draw a bar graph for plant mass versus temperature and interpret it.

Explain why fungi that degrade dead plant materials are important to the global carbon cycle. Do you accept the text’s statement that, without these fungi, “Terrestrial environments would be radically different than they are today, and probably much less productive”? Why or why not?

Explain why fungi that degrade dead plant materials are important to the global carbon cycle. Do you accept the text’s statement that, without these fungi, “Terrestrial environments would be radically different than they are today, and probably much less productive”? Why or why not?

Lignin and cellulose provide rigidity to the cell walls of plants. But in most fungi, chitin performs this role. Why is it logical that most fungi don’t have lignin or cellulose in their cell walls?

Lignin and cellulose provide rigidity to the cell walls of plants. But in most fungi, chitin performs this role. Why is it logical that most fungi don’t have lignin or cellulose in their cell walls?

Fungi feed by                   . a. producing their own food with the help of sunlight; b. chasing and capturing other living organisms; c. growing on their food source and secreting chemicals to break it down; d. filtering bacteria out of their surroundings; e. producing spores

Lawns are sometimes fertilized with nitrate that can be washed into neighboring woodlots by rain. If the trees in that woodlot are associated with EMF, what effect might the excess nitrate have on the fungi and/or trees? a. Fungal growth may be stimulated, causing the trees to transport more nitrogen to the fungi. b. The fungi may secrete more peptidases to break down the nitrate. c. The trees may take up the nitrate directly into their roots and rely less on the fungi. d. The excess nitrate may stimulate the fungi to transport more sugar to the trees.

Under a microscope, a piece of a mushroom would look most like a. jelly. b. a tangle of string. c. grains of sugar or salt. d. foam.

Lawns are sometimes fertilized with nitrate that can be washed into neighboring woodlots by rain. If the trees in that woodlot are associated with EMF, what effect might the excess nitrate have on the fungi and/or trees? a. Fungal growth may be stimulated, causing the trees to transport more nitrogen to the fungi. b. The fungi may secrete more peptidases to break down the nitrate. c. The trees may take up the nitrate directly into their roots and rely less on the fungi. d. The excess nitrate may stimulate the fungi to transport more sugar to the trees.

Which of the following groups is made up exclusively of fungi that form symbioses with plant roots? a. ascomycetes b. basidiomycetes c. glomeromycetes d. zygomycetes

Many mushrooms are extremely colorful. One hypothesis is that the colors serve as a warning to prevent animals from eating mushrooms, much like the bright yellow and black stripes on wasps help to deter potential predators. Design an experiment to test this hypothesis.

Many mushrooms are extremely colorful. One hypothesis is that the colors serve as a warning to prevent animals from eating mushrooms, much like the bright yellow and black stripes on wasps help to deter potential predators. Design an experiment to test this hypothesis.

What characters support the classification of fungi and plants in different kingdoms?

Which of the listed options generally represents the correct order of events in fungal sexual reproduction?

Which of the following statements about fungi is/are true?

What role do pheromones play in fungal sexual reproduction?

Where and when does fertilization occur in the mushroom life cycle?

What is the importance of the extended dikaryotic stage in the life cycles of basidiomycetes and ascomycetes?

The mushroom in a basidiomycete life cycle serves the same function as the _____ in the ascomycete life cycle, which is to _____.

Which statement below about zygosporangia is/are true?

The asexual spores produced by members of the phylum Ascomycota are called _____.

Fungal species are assigned to particular phyla based on _____.

Which feature below is unique to chytrids?

Using high-speed video, researchers have measured several variables associated with sporangium discharge in various spore-shooting fungi. Based on the data in the table shown here, how do the launch speed and acceleration of Pilobolus compare with those of the other fungi? How does launch speed for each species compare with the top speed of 44 km/h reached by Jamaican athlete Usain Bolt during his 2009 world-record-setting race?

Evaluate the following statements about mushrooms. Select True or False for each statement. T/F A diploid zygote is formed when a male spore fertilizes a female spore. T/F Haploid spores are formed by meiosis in basidia. T/F A mushroom is a reproductive structure that consists largely of dikaryotic cells. T/F Mushrooms are part of the group that also includes bracket fungi, boletes, puffballs, and stinkhorns.

Evaluate the following statements about mushrooms. Select True or False for each statement. T/F A diploid zygote is formed when a male spore fertilizes a female spore. T/F Haploid spores are formed by meiosis in basidia. T/F A mushroom is a reproductive structure that consists largely of dikaryotic cells. T/F Mushrooms are part of the group that also includes bracket fungi, boletes, puffballs, and stinkhorns.

Table 29.1 mentions that chytrids are responsible for massive die-offs currently occurring in amphibians. Review Koch’s postulates; then design a study showing how you would use Koch’s postulates to test the hypothesis that chytrid infections are responsible for frog deaths.

Some fungi have elaborate mechanisms for dispersing spores. For example, the “squirt gun” fungus Pilobolus, which grows in cow dung, forcibly shoots off tiny black sporangia filled with spores. Any sporangia that are flung onto fresh grass are likely to be eaten by a grazing cow, passed through its digestive system unharmed, and deposited in a new batch of dung. The spores carried within the sporangia are perfectly positioned to grow into a new mycelium. Pilobolus is a zygomycete, and the sporangia just described produce asexual spores. In contrast, which of the following best describes what happens during the sexual phase of its life cycle? a. It produces eight ascospores in each ascus. b. It produces basidiospores that grow into mushrooms. c. It produces motile sperm and eggs. d. Hyphae from two compatible mating types fuse and form a zygosporangium.

Some fungi have elaborate mechanisms for dispersing spores. For example, the “squirt gun” fungus Pilobolus, which grows in cow dung, forcibly shoots off tiny black sporangia filled with spores. Any sporangia that are flung onto fresh grass are likely to be eaten by a grazing cow, passed through its digestive system unharmed, and deposited in a new batch of dung. The spores carried within the sporangia are perfectly positioned to grow into a new mycelium. Pilobolus is a zygomycete, and the sporangia just described produce asexual spores. In contrast, which of the following best describes what happens during the sexual phase of its life cycle? a. It produces eight ascospores in each ascus. b. It produces basidiospores that grow into mushrooms. c. It produces motile sperm and eggs. d. Hyphae from two compatible mating types fuse and form a zygosporangium.

Both asexual sporangia (shown in the photo) and zygosporangia can be found in cow dung. Make a simplified drawing that illustrates the events of plasmogamy, karyogamy, and meiosis that occur during sexual reproduction in Pilobolus. Be sure to indicate and label the zygosporangium.

Both asexual sporangia (shown in the photo) and zygosporangia can be found in cow dung. Make a simplified drawing that illustrates the events of plasmogamy, karyogamy, and meiosis that occur during sexual reproduction in Pilobolus. Be sure to indicate and label the zygosporangium.

Would you describe the association between Pilobolus and cows as a symbiotic relationship? Explain your answer.

Would you describe the association between Pilobolus and cows as a symbiotic relationship? Explain your answer.

Explain the process of extracellular digestion that occurs during the growth of Pilobolus mycelia through dung.

Explain the process of extracellular digestion that occurs during the growth of Pilobolus mycelia through dung.

Using high-speed video, researchers have measured several variables associated with sporangium discharge in various spore-shooting fungi. Based on the data in the table shown here, how do the launch speed and acceleration of Pilobolus compare with those of the other fungi? How does launch speed for each species compare with the top speed of 44 km/h reached by Jamaican athlete Usain Bolt during his 2009 world-record-setting race?

Propose an experiment to test whether Pilobolus shoots its sporangia preferentially toward light. Hypothesize why such a preference might be advantageous.

Propose an experiment to test whether Pilobolus shoots its sporangia preferentially toward light. Hypothesize why such a preference might be advantageous.