F u n g i = ]
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F u n g i = ]
*sandy* Wed Dec 10, 2008 11:28 am
Fungi :
What is fungi ?
A fungus is a eukaryotic organism that is a member of the kingdom Fungi . The fungi are organisms possessing a chitinous cell wall. The majority of species grow as multicellular filaments called hyphae forming a mycelium; some fungal species also grow as single cells. Sexual and asexual reproduction of the fungi is commonly via spores, often produced on specialized structures or in fruiting bodies.
Cell Structure ?
A living cell is a complex, multi-functional unit. Even the simplest of cells performs a large array of different tasks and functions. Despite our size prejudice, which makes us view cells as very tiny, they are very large places at the level that matters, which is the chemical level.Cells come in two basic types. Read the Prokaryotic and Eukaryotic Cells essay for a discussion of the differences between these cells. Prokaryotic cells are found in bacteria, including both Archaebacteria and Eubacteria, and including the blue-green algae. Eukaryotic cells are found in animals, plants, Fungi and protists.
1 ) cell wall :
The cell wall, which is very different from the plasma membrane. Cells with cell walls also have plasma membranes; the wall can't perform the diffusion barrier tasks of the plasma membrane. One of the primary functions of the cell wall is physical support.
Obataining Food ( Nutrition ) :
Fungi nutrition:
Unlike members of the plant kingdom that use chlorophyll to produce their own food, fungi do not have chlorophyll and must obtain their food from other sources. Fungi obtain food in one, or a combination, of three ways :
Fungi act as parasites and feed on living things, usually doing some degree of harm. Parasitic fungi use enzymes to break down tissues. Examples: the "Honey
Reproduction:
[ Asexual Reproduction ]
Asexual reproduction via vegetative spores or through mycelial fragmentation is common in many fungal species and allows more rapid dispersal than sexual reproduction. In the case of the "Fungi imperfecti" or Deuteromycota, which lack a sexual cycle, it is the only means of propagation. Asexual spores, upon germination, may found a population that is clonal to the population from which the spore originated, and thus colonize new environments.
[ Sexual Reproduction ]
Sexual reproduction introduces the possibility of variation into a population, and this is why most fungi have a sexual phase. To achieve sexual reproduction it is necessary to have two mating type haploid nuclei (n + n), or a diploid (2n) nucleus. In the case of the two haploid nuclei they must fuse to form a diploid first, but once fused the nuclei undergo meiosis, which is the reduction division that potentially brings about variation in the progeny. These event are followed by the formation of spores, which in most cases are resting spores that can withstand adverse conditions.
Types :
1 The Ascomycota, commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota. These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This division includes morels, a few mushrooms and truffles, single-celled yeasts (e.g., of the genera Saccharomyces, Kluyveromyces, Pichia, and Candida), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts. Prominent and important genera of filamentous ascomycetes include Aspergillus, Penicillium, Fusarium, and Claviceps. Many ascomycetes species have only been observed undergoing asexual reproduction (called anamorphic species), but molecular data has often been able to identify their closest teleomorphs in the Ascomycota. Because the products of meiosis are retained within the sac-like ascus, several ascomyctes have been used for elucidating principles of genetics and heredity (e.g. Neurospora crassa).
2 Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust (fungus) and smut fungi, which are major pathogens of grains. Other important Basidiomyces include the maize pathogen,Ustilago maydis, human commensal species of the genus Malassezia, and the opportunistic human pathogen, Cryptococcus neoformans
What is fungi ?
A fungus is a eukaryotic organism that is a member of the kingdom Fungi . The fungi are organisms possessing a chitinous cell wall. The majority of species grow as multicellular filaments called hyphae forming a mycelium; some fungal species also grow as single cells. Sexual and asexual reproduction of the fungi is commonly via spores, often produced on specialized structures or in fruiting bodies.
Cell Structure ?
A living cell is a complex, multi-functional unit. Even the simplest of cells performs a large array of different tasks and functions. Despite our size prejudice, which makes us view cells as very tiny, they are very large places at the level that matters, which is the chemical level.Cells come in two basic types. Read the Prokaryotic and Eukaryotic Cells essay for a discussion of the differences between these cells. Prokaryotic cells are found in bacteria, including both Archaebacteria and Eubacteria, and including the blue-green algae. Eukaryotic cells are found in animals, plants, Fungi and protists.
1 ) cell wall :
The cell wall, which is very different from the plasma membrane. Cells with cell walls also have plasma membranes; the wall can't perform the diffusion barrier tasks of the plasma membrane. One of the primary functions of the cell wall is physical support.
Obataining Food ( Nutrition ) :
Fungi nutrition:
Unlike members of the plant kingdom that use chlorophyll to produce their own food, fungi do not have chlorophyll and must obtain their food from other sources. Fungi obtain food in one, or a combination, of three ways :
Fungi act as parasites and feed on living things, usually doing some degree of harm. Parasitic fungi use enzymes to break down tissues. Examples: the "Honey
Reproduction:
[ Asexual Reproduction ]
Asexual reproduction via vegetative spores or through mycelial fragmentation is common in many fungal species and allows more rapid dispersal than sexual reproduction. In the case of the "Fungi imperfecti" or Deuteromycota, which lack a sexual cycle, it is the only means of propagation. Asexual spores, upon germination, may found a population that is clonal to the population from which the spore originated, and thus colonize new environments.
[ Sexual Reproduction ]
Sexual reproduction introduces the possibility of variation into a population, and this is why most fungi have a sexual phase. To achieve sexual reproduction it is necessary to have two mating type haploid nuclei (n + n), or a diploid (2n) nucleus. In the case of the two haploid nuclei they must fuse to form a diploid first, but once fused the nuclei undergo meiosis, which is the reduction division that potentially brings about variation in the progeny. These event are followed by the formation of spores, which in most cases are resting spores that can withstand adverse conditions.
Types :
1 The Ascomycota, commonly known as sac fungi or ascomycetes, constitute the largest taxonomic group within the Eumycota. These fungi form meiotic spores called ascospores, which are enclosed in a special sac-like structure called an ascus. This division includes morels, a few mushrooms and truffles, single-celled yeasts (e.g., of the genera Saccharomyces, Kluyveromyces, Pichia, and Candida), and many filamentous fungi living as saprotrophs, parasites, and mutualistic symbionts. Prominent and important genera of filamentous ascomycetes include Aspergillus, Penicillium, Fusarium, and Claviceps. Many ascomycetes species have only been observed undergoing asexual reproduction (called anamorphic species), but molecular data has often been able to identify their closest teleomorphs in the Ascomycota. Because the products of meiosis are retained within the sac-like ascus, several ascomyctes have been used for elucidating principles of genetics and heredity (e.g. Neurospora crassa).
2 Members of the Basidiomycota, commonly known as the club fungi or basidiomycetes, produce meiospores called basidiospores on club-like stalks called basidia. Most common mushrooms belong to this group, as well as rust (fungus) and smut fungi, which are major pathogens of grains. Other important Basidiomyces include the maize pathogen,Ustilago maydis, human commensal species of the genus Malassezia, and the opportunistic human pathogen, Cryptococcus neoformans
*sandy*- Posts : 10
Join date : 2007-12-08
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