slime mold
slime mold or slime fungus, a heterotrophic organism once regarded as a fungus but later classified with the Protista . In a recent system of classification based on analysis of nucleic acid (genetic material) sequences, slime molds have been classified in a major group called the eukarya (or eukaryotes ), which includes plants and animals. There are two groups of slime molds, the plasmodial slime molds of the phylum (division) Myxomycota and the cellular slime molds of Acrasiomycota.
Slime molds have complex life cycles that may be divided into an animallike motile phase, in which growth and feeding occur, and a plantlike, immotile, reproductive phase. The motile phase is commonly found under rotting logs and damp leaves, where cellulose is abundant. It consists in the cellular slime molds of solitary, amebalike cells, and in the Myxomycota of a coenocytic (multinucleate) mass of protoplasm called a plasmodium, which creeps about by ameboid movement. Plasmodia often grow to a diameter of several inches and are frequently brightly colored. Both types ingest solid food particles using a process called phagocytosis (see endocytosis ). They feed on living microorganisms, such as bacteria and yeasts, as well as decaying vegetation. Before entering the reproductive stage, a plasmodium moves to a drier, better-lit place, such as the top of a log. In the amebalike, or cellular, slime molds, up to 125,000 individual cells aggregate and flow together, forming a multicellular mass called a pseudoplasmodium that resembles a slug and crawls about before settling in a location with acceptable warmth and brightness.
In the reproductive stage the plasmodium or pseudoplasmodium is transformed into one or more reproductive structures called fruiting bodies, each consisting of a stalk topped by a spore-producing capsule that resembles the reproductive structures of many fungi. Eventually the cellulose-walled spores are released and dispersed; they germinate in wet places, releasing naked cells. In a typical plasmodial slime mold the germinated spores go through an ameboid or flagellated swimming stage, followed by sexual fusions and cell divisions. The diploid ameboid cell (i.e., the zygote) grows and its nucleus divides repeatedly, resulting in the formation of a new plasmodium. Under adverse conditions a plasmodium may be transformed into a hard, dry, inactive mass called a sclerotium. Resistant to desiccation, it becomes a plasmodium again when favorable conditions return.
In the case of the cellular slime molds, each spore released becomes a single ameba, which feeds individually until starving cells release a chemical signal that causes them to aggregate into a new pseudoplasmodium, and the process is repeated. In sexual reproduction two haploid amebas fuse, then engulf surrounding amebas, forming a single organism called a macrocyst. The macrocyst then undergoes meiosis and mitosis and releases haploid individuals.
There are about 65 cellular and 500 known plasmodial slime mold species, found in forests and sometimes lawns throughout the world. In a few species the plasmodium, under favorable conditions, may cover an area of several square feet. A slime mold is the cause of clubroot , a disease of cabbage and related plants.
Bibliography: See J. T. Bonner, The Cellular Slime Molds (2d ed. 1985).
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Some things we know about aliens.(Critical essay)
Magazine article from: Yearbook of English Studies; 7/1/2007; ; 700+ words
; ...trope of the new is the Future; of the other, the Alien. The Slime Molds of Garrota SF aliens are descended from the prodigies of early...are our shadows, and we are theirs. [...] the intelligent slime molds of Garrota considered human beings with all their technology...
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All Taxa Biodiversity Inventory (ATBI). (In Brief).
Magazine article from: Environment; 7/1/2003; ; 54 words
; ...Mountains National Park has identified 334 species new to science and another 2,192 new to the park. These include mainly insects, spiders, worms, fungi, and slime molds, along with one mammal new to the park: the evening bat. National Parks, May/June.
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Essential plant pathology. (CD-ROM included).(Brief Article)(Book Review)
Magazine article from: SciTech Book News; 3/1/2007; 137 words
; ...Illinois at Urbana-Champaign) introduce the field. Chapters include case studies, study questions, interesting trivia (e.g., slime molds inspired The Blob), and references to the companion CD-ROM, which has links for Internet research. Appended material includes...
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TerraCyte broad spectrum algaecide/fungicide.
Magazine article from: California Fairways; 3/1/2004; 190 words
; ...environmentally friendly granular that can be added directly onto growing plants and turf for the prevention and control of moss, algae, slime, molds, liverwort and their spores. Non-phytotoxic and safe for use on all types of plants and turf, the elements of TerraCyte are...
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Mushrooms and Other Fungi of the Midcontinental United States.(Brief article)(Book review)
Newspaper article from: Internet Bookwatch; 5/1/2008; 192 words
; ...is most likely to be seen, and its edible or toxic characteristics. An additional section devoted to commonly encountered slime molds rounds out this superb reference, written by emeritus professor of biology Donald Huffman. Useful to professional biologists...
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A letter from our director and CEO.(First Word)
Magazine article from: ROM Magazine; 3/22/2009; ; 500 words
; ...graphic. In its lower left corner the story starts some three billion years ago with blue-green algae and bacteria, leading to slime molds, green algae, and fungi. These simple ancestors of ours prevailed for, well, eons. The animal kingdom comes into sight about...
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Getting the Right Right: Liberals (and others) write conservative history.
Magazine article from: National Review; 1/28/2002; ; 700+ words
; ...few historians are themselves conservative. Many despise conservatism. Just as most biologists don't want to specialize in slime molds, hardly any modern historians want to spend their careers examining a subject they find so distasteful. They would much rather...
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The 11 heterograms of Farthalomew Splib.(Short Story)
Magazine article from: Word Ways; 2/1/2005; ; 455 words
; ...show. If he fails, then my entire estate shall go to my pet research project, the Society for the Preservation of Anhydrous Slime Molds. * Simple enough--but was there a catch? Reading Grubs, a rambling saga of unlikely characters and implausible plot, Wally...
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Superintendent role essential in discovery of new turf disease.(RESEARCH UPDATE)
Magazine article from: California Fairways; 9/1/2005; 700+ words
; ...virus. The only organisms similar that are known are a small group of unusual pathogens of ocean-dwelling plants known as net slime molds. The organism destroys turf foliage by invading the leaf mesophyll cells, filling them with hundreds of small spindle-shaped...
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Slime Molds
Book article from: World of Microbiology and Immunology
...Acrasiomycota) and the plasmodial slime molds (Phylum Myxomycota...fungi . The two groups of slime molds are considered separately...below. Species in the cellular slime mold group are microscopic during...haploid amoebas of a cellular slime mold aggregate into a mass of ...
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mold
Book article from: The Columbia Encyclopedia, Sixth Edition
...organic matter. Among the commonest forms is the black bread mold ( Rhizopus nigricans ), which grows on decaying vegetables...diseases (see ergot ). Some organisms traditionally thought to be mold (e.g., slime molds ) have now been placed in the kingdom Protista . Bibliography...
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clubroot
Book article from: The Columbia Encyclopedia, Sixth Edition
...Cruciferae ( mustard family). It is induced by a plasmodial slime mold that attacks the roots, causing, in the cabbage, undeveloped...finger-and-toe from the swollen shape it gives to roots. Plasmodial slime molds (phylum, or division, Myxomycota) are classified in the...
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Myxomycota
Book article from: The Columbia Encyclopedia, Sixth Edition
see slime mold .
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Acrasiomycota
Book article from: The Columbia Encyclopedia, Sixth Edition
see slime mold .
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