Cilia and Flagella

Ciliated Epithelial Cells
This colored scanning electron micrograph (SEM) of a section through the wall of a trachea (wind pipe) shows ciliated epithelial cells. Credit: Steve Gschmeissner/Science Photo Library/Getty Images

Cilia and Flagella

Both prokaryotic and eukaryotic cells contain structures known as cilia and flagella. These extensions from the cell surface aid in cell movement.

What Are Cilia and Flagella?

Cilia and flagella are protrusions from some cells that aid in cellular locomotion. They also help to move substances around cells and direct the flow of substances along tracts.

Cilia and flagella are formed from specialized groupings of microtubules called basal bodies.

If the protrusions are short and numerous they are termed cilia. If they are longer and less numerous (usually only one or two) they are termed flagella.

What Are Their Distinguishing Characteristics?

Typically cilia and flagella have a core composed of microtubules connected to the plasma membrane arranged in what is known as a 9 + 2 pattern. The pattern is so named because a ring of nine microtubule "doubles" has in its center two singular microtubules. This organization allows the sliding of the microtubule doubles against one another to "bend" the cilia or flagella. This type of organization is found in most eukaryotic cilia and flagella.

Where Can Cilia and Flagella Be Found?

Both cilia and flagella are found in numerous types of cells. For instance, the sperm of many animals, algae, and even ferns have flagella. Cilia can be found in areas such as the respiratory tract and female reproductive tract.

Journey into the Cell

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Your Citation
Bailey, Regina. "Cilia and Flagella." ThoughtCo, May. 31, 2016, Bailey, Regina. (2016, May 31). Cilia and Flagella. Retrieved from Bailey, Regina. "Cilia and Flagella." ThoughtCo. (accessed December 17, 2017).