Slime molds :: essays research papers

sludge mold begrime mold or max fungus,a heterotrophic organism once regarded as a fungus but later classified with the Protista. In a youthful system of classification based on analysis of nucleic acid (genetic material) sequences, begrime molds have been classified in a major group called the eukarya (or eukaryotes), which includes plants and animals. in that respect are two groups of slime molds, the plasmodial slime molds of the phylum (division) Myxomycota and the prison cellular slime molds of Acrasiomycota. Slime molds have complex life cycles that may be carve up into an animallike motile phase, in which becometh and runing 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) passel of living substance called a plasmodium, which creeps about by ameboid movement. Plasmodia often grow to a diameter of several inches and are frequently brightly colored. both(prenominal) types ingest solid food particles using a process called phagocytosis (see endocytosis). They feed on living microorganisms, such as bacteria and yeasts, as tumesce as decaying vegetation. Before entering the reproductive demo, 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 flux 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 burgeon forth in wet places, releasing naked cells. In a distinctive 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 ill conditions a plasmodium may be transformed into a hard, dry, torpid mass called a sclerotium. Resistant to desiccation, it becomes a plasmodium again when affectionate conditions return.In the case of the cellular slime molds, each spore released becomes a star 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.