Term
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Definition
| Eukaryotes that grow as single cells or as large, branching networks of multicellular filaments. Mushrooms, molds, mildews, athlete's foot, yeasts for baking/brewing. Along with land plants/animals, they are one of three major lineages of large, multicell euks that occupy terrestrial environments. |
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Term
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Definition
| Fungi absorb their nutrition from other organisms - dead or alive. |
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Term
| Why is the way that they feed special/unique? |
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Definition
| Fungi that absorb nutrients from dead organisms are the world's most important decomposers. A few types of organisms can digest the cellulose in plant cell walls, but fungi and only a handful of bacterial species are the ONLY organisms capable of completely digesting both the lignin and cellulose that make up wood. |
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Term
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Definition
| Fungi that specialize in absorbing nutrients from living organisms. When they absorb without providing any benefit in return, they loser fitness of the host organism and act as parasites. |
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Term
| Are most fungi that absorb nutrients from living organisms "bad" or beneficial?? |
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Definition
| The vast majority of fungi that live in association with other organisms benefit their hosts. They are not parasites in this case, but mutualists. |
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Term
| Describe the mutualist relationship between fungi and land plants. |
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Definition
| The roots of virtually every land plant in the world are colonized by an array of mutualistic fungi. In exchange for sugars that are synthesized by the host plant, the fungi provide the plant with water and key nutrients like nitrogen and phosphorus. Without these nutrients, the host plants grow a lot slower or even starve. |
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Term
| Because they recycle key elements such as blank, blank, and blank, and because they transfer key blank to blank, fungi have a profound influence on blank and blank |
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Definition
| Because they recycle key elements such as carbon, nitrogen, and phosphorus and because they transfer key nutrients to plants, fungi have a profound influence on productivity and biodiversity. |
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Term
| Other than their importance to life on land and intricate relationships with others, what are important practical reasons for humans to study fungi? |
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Definition
| They nourish the plants that nourish us. They affect global warming, because they are critical to the carbon cycle on land. But also, some species can cause debilitating disease in humans and crop plants. |
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Term
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Definition
| Fungi that live in close association with plant roots |
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Term
| Why is mycorrhizal fungi so important? |
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Definition
| Species grow 3 to 4 times faster in the presence of its normal mycorrhizal fungal associates than it does without them. For farmers, foresters, and ranchers, the presence of normal mycorrhizal fungi can mean the difference between profit and lost. |
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Term
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Definition
| Fungi that make their living by digesting dead plant material |
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Term
| Two basic components of the CARBON CYCLE on land: |
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Definition
1. the fixation of carbon by land plants - meaning that carbon in atmospheric CO2 is reduced to cellulose, lignin, and other complex organic compounds in the bodies of plants, and
2. the release of CO2 from plants, animals, and fungi as the result of cellular respiration - meaning the oxidation of glucose and the production of the ATP that sustains life |
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Term
| Why do sporophyte fungi play a key role in today's terrestrial environments? |
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Definition
| Well, recall from Ch 30 that cells in vascular tissue of land plants have secondary cell walls with both lignin and cellulose. Wood forms when stems grow in girth by adding layers of lignin rich vascular tissue. When trees die, fungi are the organisms that break down wood into sugars and other small organic compounds. Fungi use these molecules as food. |
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Term
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Definition
| fungi connect the two parts of the cycle |
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Term
| If fungi had not evolved the ability to digest lignin and cellulose soon after land plants evolved the ability to MAKE those compounds... what would have happened? |
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Definition
| Carbon atoms would have been sequestered in wood for millennia instead of being rapidly recycled into glucose molecules and CO2. Terrestrial environments would be radically different and probably much less productive. |
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Term
| What kinds of things can parasitic fungi cause? |
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Definition
| Athlete's foot, vaginitis, diaper rash, ringworm, pneumonia, and thrush, among other miseries. (seriously). But only about 31 species of fungi among hundreds of thousands, regularly cause illness in humans |
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Term
| Why would someone argue that fungi has done more to promote human health than degrade it? |
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Definition
| The first antibiotic that was widely used, penicillin, was isolated from a fungus, and soil-dwelling fungi continue to be the source of many of the most important antibiotics prescribed against bacterial infections. |
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Term
| Major destructive impact that fungi have on people? |
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Definition
| Through the food supply. Fungi known as rusts, smuts, mildews, wilts, and blights cause annual crop losses computed in the billions of dollars. They are particularly troublesome in what, corn, barley, and other grains. Saprophytic fungi are also responsible for enormous losses due to spoilage - particularly for fruit/vegetable growers. |
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Term
| What agent of evolution is most responsible for generating the appearance of evolutionary design? |
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Definition
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Term
| In nature, what have epidemics caused by fungi done? |
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Definition
| Killed 4 billion chesnut trees and tens of millions of American elm trees in North America. The epidemics radically altered the composition of upland and floodplain forests in the eastern United States. Before these fungal epidemics, chesnuts and elms dominated these habitats |
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Term
| Fungi have important positive impacts on the human food supply: |
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Definition
| Mushrooms! Yeast Saccharomyces cerevisiae was domesticated thousands of years ago and it and others are essential to manufacture bread, soy sauce, tofu, cheese, bear, wine, whiskey, etc. Enzymes from fungi are used to improve characteristics of foods. |
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Term
| How many species of fungi do we know about? |
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Definition
| About 80,000 species of fungi have been described and named to date, and about 1000 more are discovered each year. |
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Term
| How do we predict the actual number of fungal species? |
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Definition
| Hawksworth looked at the ratio of vascular plant species to funal species in the British isles - where the two groups are most thoroughly studied. He found there is an average of 6 species of fungus for every species of vascular plants on these islands. If this holds worldwide, then the estimated total of 275,000 vascular plant species implies there are 1.65 million species of fungi. |
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Term
| Compared with animals and land plants, fungi have simple bodies. Only two growth forms can occur among them, what are they? |
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Definition
1. Single-celled forms called yeasts and
2. Multicellular, filamentous structures called mycelia
Many species grow either as one or the other, but some adopt both growth forms |
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Term
| Most fungi form what growth form? And why? |
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Definition
| Most fungi form mycelia. This body type is so fundamental to the absorptive mode of life |
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Term
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Definition
| Any fungus growing as a single-celled form. |
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Term
| Mycelium (plural mycelia) |
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Definition
| A mass of underground filaments (hyphae) that form the body of a fungus. |
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Term
| What type of fungus do biologists study most and why? |
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Definition
| Because most fungi form mycelia and because this body type is so fundamental to the absorptive mode of life, most studies of fungal morphology have focused on them |
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Term
| The nature of the fungal mycelium |
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Definition
| If food sources are plentiful, mycelia can be long lived and grow to be extremely large. Mycelia constantly grow in the direction of food sources and die back in areas where food is running out. The body shape of a fungus can change almost continuously throughout its life. REcent data shows that the individual filaments that make up a mycelium live, on average, only about five days |
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Term
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Definition
| The filaments within a mycelium. They can be haploid or heterokaryotic. Long, narrow filaments that branch frequently. |
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Term
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Definition
| Each cell contains several haploid nuclei from different parents. Most heterokaryotic hyphae are dikaryotic, one haploid nucleus from each parent |
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Term
| How are hyphae assembled within a mycelium? |
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Definition
| They are long, narrow filaments that branch frequently. In most fungi, each filament is broken into cell-like compartments by cross-walls called septa (singular septum. Septa do not close off segments of hyphae completely. Instead, gaps called pores enable a wide variety of materials, even organelles and nuclei, to flow from one compartment to the next. |
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Term
| Coenocytic (See no sit ick) |
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Definition
| fungal species that lack septa entirely |
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Term
| What is good about fungus' tiny size? |
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Definition
| Fungal mycelia can penetrate tiny fissures in soil and absorb nutrients that are inaccessible to plant roots. |
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Term
| What is the down side to the extraordinarily high surface area of mycelium? |
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Definition
| The amount of water that evaporates from an organisms is a function of its surface area - these organisms are prone to drying out. As a result, fungi are most abundant in moist habitats. |
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Term
| Why do fungi have the highest surface-to-volume ratios observed in multicellular organisms? |
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Definition
| Because mycelia are composed of complex, branching networks of extremely thin hyphae |
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Term
| What kind of reproductive cells do fungi have? |
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Definition
| Spores... they are produced by sexual or asexual reproduction and are resistant to drying. |
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Term
| Mycelia are an WHAT that supports the WHAT of fungi?? |
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Definition
| Mycelia are an adaptation that supports the abdoptive lifestyle of fungi. |
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Term
| The only thick, fleshy structures that fungi produce are WHAT? |
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Definition
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Term
| What structures that arise from mycelia do not absorb food? |
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Definition
| Mushrooms, puffballs, and other dense, multicellular structures that arise from mycelia do not absorb food. Instead, they function in reproduction |
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Term
| Fungus reproductive structures - mushrooms |
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Definition
| Relatively few species of fungi make the reproductive organs called mushrooms. Typically, they are the only part of a fungus that is exposed to the atmosphere, where drying is a problem. The mass of filaments on the inside of mushrooms is protected from drying by the densely packed hyphae forming the surface |
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Term
| 4 distinctive reproductive structures of sexually producing fungus |
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Definition
| Swimming gametes and spores, zygosporangia, basidia, and asci |
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Term
| Sexual reproducing fungus, reproductive structure 1.Swimming gametes and spores -? |
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Definition
| certain species that live in water or wet soils, the spores that are produced during asexual rep. have flagella as do the gametes produced during sexual rep. These are the only motile cells known in fungi. Species with swimming gametes are traditionally known as chytrids |
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Term
| Species with swimming gametes are traditionally known as what? |
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Definition
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Term
| Sexual reproducing fungus, reproductive structure 2. zygosporangia |
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Definition
| Haploid hyphae from two individuals meet and become yoked together. Cells from yoked hyphae fuse to form a distinctive spore-producing structure called a zygosporangium. Species with a zygosporangium are known as zygomycetes |
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Term
| Species with a zygosporangium are known as what? |
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Definition
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Term
| Sexual reproducing fungus, rep. structure 3. basidia |
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Definition
| Inside a mushroom, bracket, or puffball, specialized cells called basidia form at the ends of hyphae and produce spores. Species with basidia are traditionally called basidiomycetes. |
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Term
| Species with basidia are traditionally called what? |
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Definition
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Term
| Sexual reproducing fungus, rep. structure 4. asci |
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Definition
| Inside cups, morels, and some other types of aboveground reproductive structures, specialized cells called asci form at the ends of hyphae and produce spores. Species with asci are traditionally known as ascomycetes. |
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Term
| Species with asci are traditionally known as what? |
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Definition
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Term
| Fungi are most closely related to what group? |
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Definition
| Fungi are much more closely related to animals than they are to land plants |
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Term
| Why are fungal infections in humans much more difficult to treat than bacterial infections? |
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Definition
| Because of their close evolutionary relationship. Fungi and humans share a common ancestor relatively recently. As a result, their enzymes and cell components are similar in structure and function. Drugs that disrupt fungal enzymes and cells are also likely to damage humans |
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Term
| In addition to the DNA sequence data, three key morphological traits link animal and fungi |
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Definition
1. most animals and fungi synthesize the tough structural material called chitin. It is a prominent component of the cell walls of fungi
2. The flagella that develop in chytrid spores and chytrid gametes are similar to those in animals. as in animals, the flagella in chytrids are single, located at the back of reproductive cells, and move in a whiplash manner.
3. Both animals and fungi store food by synthesizing the polysaccharide glycogen |
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Term
| What are the monophyletic groups and paraphyletic groups that fungal species form? |
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Definition
| The chytrids and zygomycetes form a paraphyletic group. The glomeromycota group is monophyletic. the basidiomycetes are monophyletic, forming a lineage called Basidiomycota, or club fungi. The ascomycetes are monophyletic forming a lineage called Ascomycota, or sac fungi. Together, the Basidiomycota and Ascomycota form a monophyletic group. And finally, the single-celled eukaryotes called microsporidians are actually fungi. |
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Term
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Definition
| Any close and prolonged physical relationship between individuals of two different species. |
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Term
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Definition
| A symbiotic relationship between two organisms that is beneficial to one organism (the parasite) but detrimental to the host |
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Term
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Definition
| A symbiotic relationship between two organisms (mutualists) that benefits both |
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Term
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Definition
| A symbiotic relationship in which one organism (the commensal) benefits and the other (the host) is not harmed. |
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Term
| How do researchers explore the nature of fungi-plant symbioses in detail? |
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Definition
| They have used isotopes as tracers for specific elements. For example, to test hypothesis that fungi obtain food in form of carbon-containing compounds from plants, they introduced radioactively labeled CO2 into the air surrounding plants that do or do not have symbiotic fungi. If plants feed their fungal symbionts, than labeled carbon compounds should be transferred from the plant to the fungi. |
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Term
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Definition
| Fungi whose hyphae form a dense network that covers their host plant's roots but do not enter the root cells |
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Term
| Arbuscular mycorrhizal fungi |
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Definition
| Fungi whose hyphae enter the root cells of their host plants. Also called ENDOmycorrhizal fungi |
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Term
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Definition
| Fungi that live in the aboveground part of plants. They live in close association with the aboveground tissues of land plants - leaves and stems. They are much more common and diverse than people suspected and some of the endophytes are mutualistic. |
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Term
| What does EMF stand for? Where is it found? |
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Definition
| EMF is ectomycorrhizal fungi. EMF are found on many of the tree species in the temperate regions of the world where warm summers alternate with cold winters. |
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Term
| How do these trees and EMF interact once they start living together? |
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Definition
| In habitats with abundant EMF, nitrogen atoms tend to remain tied up in dead tissues, in amino acids and nucleic acids instead of being available in the soil. The hyphae of EMF penetrate decaying material and release enzymes called peptidases that cleave the peptide bonds between amino acids in dead tissues. The aminos released by the reaction are absorbed by the hyphae and transported to spaces btwn the root cells of trees, where the plant can absorb them. |
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Term
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Definition
| EMF are also able to acquire phosphate ions that are bound to soil particles and transfer the ions to host plants. In return, the fungi receive sugars and other complex carbon compounds from the tree. |
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Term
| What is the major difference between EMF and AMF? |
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Definition
| In contrast to the hyphae of ectomycorrhizal fungi, the hyphae of arbuscular mycorrhizal fungi grow INTO the cells of root tissue. |
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Term
| What is the key point about AMF?1 |
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Definition
| the hyphae of AMF penetrate the cell wall and contact the plasma membrane of root cells directly. The highly branched hyphae inside the plant cell wall are thought to be an adaptation that increases the surface area available for exchange of molecules between the fungus and its host |
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Term
| AMF do not form a tight sheath around roots like EMF does... what do they do instead? |
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Definition
| Instead, they form a pipeline extending from inside plant cells in the root to the soil well beyond the root |
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Term
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Definition
| Arbuscular mycorrhizal fungi are found in a whopping 80 percent of all land plant species and are particularly common in grasslands and in the forests of tropical habitats. Also widespread in temperate climates |
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Term
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Definition
| Plant tissues decompose quickly in the grasslands and tropical forests because growing season is long and warm. So nitrogen is readily available to plants. Phosphorus is in short supply because it leaches out of soil exposed to high rainfall. Their most important function (AMF) is to transfer phosphorus atoms from the soil to the host plant |
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Term
| AMF are extremely important in soil formation... why? |
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Definition
| The cell walls of their hyphae contain large amounts of a glycoprotein called GLOMALIN. When cells die, the glomalin enriches the organic matter in soil and helps bind organic compounds to sand/clay particles. |
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Term
| Do fungi take up residence with species other than land plants? |
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Definition
| YES. Lichens and also some ant species actively farm fungi inside their colonies. The ants fertilize and "weed" the fungal gardens, then harvest the fungi for food. |
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Term
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Definition
| Mutualistic partnership between a speceis of ascomycete and either a cyanobacterium or an alga. |
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Term
| EMF mine what and SOME what for plants where? And AMF mind what for plants where? |
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Definition
| EMF mine nitrogen and SOME phosphorus for plants in temperate forests; AMF mine phosphorus for plants in grasslands and tropics as well as temperate regions |
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Term
| Two key adaptations that make fungi such effective decomposers? |
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Definition
| The large surface area of a mycelium makes nutrient absorption exceptionally efficient. Saprophytic fungi can grow toward the dead tissues that supply their food. |
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Term
| Large molecules like WHAT, CANNOT diffuse across the plasma membranes of hyphae? |
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Definition
| Large molecules such as starch, lignin, cellulose, proteins, and RNA cannot diffuse across the plasma membranes of hyphae |
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Term
| What molecules CAN enter the cytoplasm through hyphae? |
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Definition
| Only sugars, amino acids, nucleic acids, and other small molecules can enter the cytoplasm through hyphae. |
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Term
| Instead of digesting food inside a stomach or food vacuole, how to fungi do it? |
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Definition
| They synthesize digestive enzymes and then secrete them outside their hyphae, into their food. This is extracellular digestion |
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Term
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Definition
| Digestion that takes place outside the organism |
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Term
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Definition
| Fusion of the cytoplasm of two individuals. Occurs in many fungi. |
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Term
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Definition
| Fusion of two haploid nuclei to form a diploid nucleus. Occurs in many fungi, and in animals and plants during fertilization of gametes |
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Term
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Definition
| A spore-producing structure found in seed plants some protists and some fungi (like chytrids) |
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Term
| Absorptive lifestyle of Fungi > Microsporidia |
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Definition
| Most parasitize insects or fish... and because they enter the interior of host cells, they are called intracellular parasites |
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Term
| Life cycle of Fungi > Microsporidia |
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Definition
| Variation in life cycles is extensive. Some species reproduce only asexually, others produce diff. types of sexual or asexual spores, some have to infect several hosts to complete their life cycle. |
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Term
| Absorptive lifestyle of Fungi > Chytrids |
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Definition
| Enzymes allow them to digest cellulose. Important decomposers of plant material in wet environments. Many are parasitic and some cause disease epidemics in algae/aquatic insects. others parasitize mosses, ferns, angiosperms. but mutualist chytrids are important for deer, cow, elk, etc. |
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Term
| Life cycle of Fungi > Chytrids |
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Definition
| During asexual, they produce swimming spores that have flagellum. Some do sex/asex (Alternation of generations) the only fungal species to do so. |
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Term
| Absorptive lifestyle of Fungi > Zygomycetes |
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Definition
| Many members of zygomycete lineages are saprophytes and live in plant debris. Some parasitize other fungi though or are important parasites of insects and spiders |
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Term
| Life cycle of Fungi > Zygomycetes |
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Definition
| Asexual rep. extremely common. Ball-like sporangia produced at tips of hyphae that form stalks. Mitosis results in spores, dispersed by wind. During SEXUAL rep, fusion of hyphae occurs only btwn individuals of diff. mating types |
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