History Of Fungi

Familiar as visible reproductive forms such as mushrooms, morels, and puffballs, but more often single-celled yeasts and other microscopic forms invisible to the naked eye, fungi can be defined as nonplant, nonanimal eukary-otes that develop from fungal spores. The largest include the shelf fungi that grow on the base of trees.

Although sometimes similar to, and confused with, members of the protoctist kingdom ("protozoans"), fungi never display the cell appendages known as undulipodia at any time in their life cycle. Undulipodia, sometimes called flagella, are in fact distinct from bacte rial flagella made of flagellin proteins. Undulipodia—the generic term—have many familiar examples: cilia, sperm tails, and eukary-otic (but not prokaryotic) flagella. Cross-sections of these structures reveal an internal symmetry of nine pairs of microtubules. Thus true undulipodia, common to other kingdoms made of eukaryotic cells, were either never present or, more probably, lost in the ancestors of fungi during the course of evolution. This makes sense, because fungi, which disperse by airborne (or animal-attached) spores, excel at settling land and soil. Swimming by undulation is impossible outside water.

Although fungi sometimes mate, their sexual activities are radically different from those of plants or animals. A single species, for example, may display thousands of distinct mating types; all except those of the exact same mating type cannot mate with each other. Fungi also differ from plants and animals in that they do not typically form cells with two sets of chromosomes; the result of mating fungal threads (hyphae) or spherical cells are new structures with only one set of chromosomes, or cells with two nuclei that do not merge (or merge only directly before spore formation; see below), as occurs with plants and animals.

Worm Farming

Worm Farming

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