Form and Behavior
Eukaryotic flagella are supported by microtubules in a characteristic arrangement, with nine fused pairs surrounding two central singlets. These arise from a basal body or kinetosome, with microtubule roots that are an important part of the cell's brain. In some, for instance, they support a cytostome or mouth, where food is ingested. The flagella often supports hairs, called mastigonemes, or contain rods. Their ultrastructure plays an important role in classifying eukaryotes.
In protoctists and microscopic animals, flagella are generally used for propulsion. They may also be used to create a current that brings in food. In most things, one or more flagella are located at or near the anterior of the cell e.g. Euglena. Often there is one directed forwards and one trailing behind. Among animals, fungi, and Choanozoa, which make up a group called the opisthokonts, there is a single posterior flagellum. They are from the phylum Mastigophora. They can cause diseases and they can make their own food. They reproduce by binary fission.
Read more about this topic: Flagellate
Famous quotes containing the words form and, form and/or behavior:
“Now only a dent in the earth marks the site of these dwellings, with buried cellar stones, and strawberries, raspberries, thimble-berries, hazel-bushes, and sumachs growing in the sunny sward there.... These cellar dents, like deserted fox burrows, old holes, are all that is left where once were the stir and bustle of human life, and “fate, free will, foreknowledge absolute,” in some form and dialect or other were by turns discussed.”
—Henry David Thoreau (1817–1862)
“To the United States the Third World often takes the form of a black woman who has been made pregnant in a moment of passion and who shows up one day in the reception room on the forty-ninth floor threatening to make a scene. The lawyers pay the woman off; sometimes uniformed guards accompany her to the elevators.”
—Lewis H. Lapham (b. 1935)
“There are ... two minimum conditions necessary and sufficient for the existence of a legal system. On the one hand those rules of behavior which are valid according to the system’s ultimate criteria of validity must be generally obeyed, and on the other hand, its rules of recognition specifying the criteria of legal validity and its rules of change and adjudication must be effectively accepted as common public standards of official behavior by its officials.”
—H.L.A. (Herbert Lionel Adolphus)