*** Other subcellular features: cell wall — pseudopod — cytoskeleton — mitotic spindle — flagellum — cilium

Many bacteria, such as Vibrio, are monoflagellated and have a single flagellum at one pole of the cell.

Others possess a single flagellum that is kept inside the cell wall.

Other cell types, such as trypanosomatid parasites, have a MTOC but it is permanently found at the base of a flagellum.

A flagellum (; plural: flagella ) is a lash-like appendage that protrudes from the cell body of certain prokaryotic and eukaryotic cells.

The canonical role of the flagellum is locomotion but it also often has function as a sensory organelle, being sensitive to chemicals and temperatures outside the cell.

An example of a eukaryotic flagellate cell is the mammalian sperm cell, which uses its flagellum to propel itself through the female reproductive tract.

The bacterial flagellum is driven by a rotary engine ( the Mot complex ) made up of protein, located at the flagellum's anchor point on the inner cell membrane.

The clockwise rotation of a flagellum is suppressed by chemical compounds favorable to the cell ( e. g. food ), but the motor is highly adaptive to this.

V. cholerae is facultatively anaerobic and has a flagellum at one cell pole.

The transverse flagellum is ribbon-like and coiled, provides most of the force propelling the cell, and often imparts to it a distinctive whirling motion, which is what gives them their name.

A variety of different morphological forms appear in the life cycles of trypanosomatids, distinguished mainly by the position, length and the cell body attachment of the flagellum.

Modern terminology is derived from the Greek ; " mastig ", meaning whip ( referring to the flagellum ), and a prefix which indicates the location of the flagellum on the cell.

The flagellum is found anterior of nucleus and flagellum not attached to the cell body.

In trypomastigotes the kinetoplast is near the posterior end of the body, and the flagellum lies attached to the cell body for most of its length by an undulating membrane.

A rarer morphology where the flagellum posterior of nucleus, passing through a long groove in the cell.

The cell body is shown in orange and the flagellum is in red.

The cell body is shown in orange and the flagellum is in red.

The cell body is shown in orange and the flagellum is in red.

In kinetoplastids with two flagella most forms have a leading and trailing flagellum, the latter of which may or may not be attached to the side of the cell.

Leishmania cells have two morphological forms: promastigote ( with an anterior flagellum ) in the insect host, and amastigote ( without flagella ) in the vertebrate host.

Two areas from a blood smear from a patient with African trypanosomiasis, thin blood smear stained with Giemsa: Typical trypomastigote stages ( the only stages found in patients ), with a posterior kinetoplast, a centrally located nucleus, an undulating membrane, and an anterior flagellum.

The flagellum is at the anterior of the cell, and the tentacles surround it, often capturing small prey drawn in by its current.

The anterior or tinsel flagellum is covered with lateral bristles or mastigonemes, while the other flagellum is whiplike, smooth, and usually shorter, or sometimes reduced to a basal body.

* Epimastigote-Basal body anterior of nucleus, with a long flagellum attached along the cell body.

In both cases there are four basal bodies anterior to a prominent feeding groove, and one flagellum is directed back through the cell, emerging from the groove.

The flagellum propels swimming cells through the water column and creates water currents through the microvilli, which trap foodstuff such as bacteria and detritus. The arrangement of organelles in Proterospongia appears consistent with other choanoflagellates and is characterized by an anterior dictyosome under the flagellar base, a central nucleus, peripheral mitochondria and a posterior food vacuole.

The kinetoplast is found closely associated with the basal body at the base of the flagellum and all species of trypanosomatid have a single nucleus.

Kinetoplastids are eukaryotic and possess normal eukaryotic organelles, for example the nucleus, mitochondrion, golgi apparatus and flagellum.

In section they are very different with the ovaries densely filled with nutrient-packed ova ( see ovum and photograph ) and the testes densely filled with sperm, which consist of little more than a nucleus and flagellum.

Spermatozoa are characterized by an elongated shape with a compact nucleus and a flagellum.

* Trypomastigote-Basal body posterior of nucleus, with a long flagellum attached along the cell body.

Among animals, fungi, and Choanozoa, which make up a group called the opisthokonts, there is a single posterior flagellum.

The bacterial flagellum is frequently invoked as an example of irreducible complexity.

Behe asserts that the absence of any one of these proteins causes the flagella to fail to function, and that the flagellum " engine " is irreducibly complex as if we try to reduce its complexity by positing an earlier and simpler stage of its evolutionary development, we get an organism which functions improperly.

The needle's base has ten elements in common with the flagellum, but it is missing forty of the proteins that make a flagellum work.

" Dembski's critique of this position is that phylogenetically, the TTSS makes an unlikely precursor to the flagellum given that TTSS is found in a narrow range of bacteria which makes it seem to be a late innovation, whereas flagella are widespread throughout many bacterial groups, which implies it was an early innovation.

The whip-like tail ( flagellum ) of the sperm is studded with ion channels formed by proteins called CatSper.

Under the microscope, a Bdellovibrio appears as a comma-shaped motile rod that is about 0. 3-0. 5 by 0. 5-1. 4 µm in size with a barely discernible flagellum.

Another notable feature of Bdellovibrio is the sheath that covers its flagellum.

The bacterial flagellum is made up of the protein flagellin.

Amphitrichous bacteria have a single flagellum on each of two opposite ends ( only one flagellum operates at a time, allowing the bacteria to reverse course rapidly by switching which flagellum is active ).

Other bacteria, such as Spirochetes, have a specialized type of flagellum called an " axial filament " that is located in the periplasmic space, the rotation of which causes the entire bacterium to move forward in a corkscrew-like motion.

The archaeal flagellum ( Archaellum ) is superficially similar to the bacterial ( or eubacterial ) flagellum ; in the 1980s they were thought to be homologous on the basis of gross morphology and behavior.