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A flagellum (/ f l ə ˈ dʒ ɛ l əm /; pl.: flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores , and from a wide range of microorganisms to provide motility.
Flagella in eukaryotes are supported by microtubules in a characteristic arrangement, with nine fused pairs surrounding two central singlets. These arise from a basal body. In some flagellates, flagella direct food into a cytostome or mouth, where food is ingested. Flagella role in classifying eukaryotes.
The evolution of flagella is of great interest to biologists because the three known varieties of flagella – (eukaryotic, bacterial, and archaeal) each represent a sophisticated cellular structure that requires the interaction of many different systems.
Flagella are whip-like structures protruding from the bacterial cell wall and are responsible for bacterial motility (movement). The arrangement of flagella about the bacterial cell is unique to the species observed. Common forms include: Monotrichous – Single flagellum; Lophotrichous – A tuft of flagella found at one of the cell poles
Eukaryotic flagella—those of animal, plant, and protist cells—are complex cellular projections that lash back and forth. Eukaryotic flagella are classed along with eukaryotic motile cilia as undulipodia [17] to emphasize their distinctive wavy appendage role in cellular function or motility. Primary cilia are immotile, and are not undulipodia.
By cooperatively moving their flagella, choanocytes filter particles out of the water and into the spongocoel, and out through the osculum.This improves both respiratory and digestive functions for the sponge, pulling in oxygen and nutrients and allowing a rapid expulsion of carbon dioxide and other waste products.
They have a ribbon-like transverse flagellum with multiple waves that beats to the cell's left, and a more conventional one, the longitudinal flagellum, that beats posteriorly. [18] [19] [20] The transverse flagellum is a wavy ribbon in which only the outer edge undulates from base to tip, due to the action of the axoneme which runs along it ...
Movement of the flagellum draws water through the collar, and bacteria and detritus are captured by the microvilli and ingested. [13] Water currents generated by the flagellum also push free-swimming cells along, as in animal sperm. In contrast, most other flagellates are pulled by their flagella. [citation needed]