1: Microfilaments thicken the cortex around the inner edge of a cell; like rubber bands, they resist tension. Microtubules are found in the interior of the cell where they maintain cell shape by resisting compressive forces. Intermediate filaments are found throughout the cell and hold organelles in place.

Microtubules are major components of the cytoskeleton. They are found in all eukaryotic cells, and they are involved in mitosis, cell motility, intracellular transport, and maintenance of cell shape. Microtubules are composed of alpha- and beta-tubulin subunits assembled into linear protofilaments.

Primary cilia are microscopic sensory antennae that cells in many vertebrate tissues use to gather information about their environment. In the kidney, primary cilia sense urine flow and are essential for the maintenance of epithelial architecture.

The function of cilia is to move water relative to the cell in a regular movement of the cilia. This process can either result in the cell moving through the water, typical for many single-celled organisms, or in moving water and its contents across the surface of the cell.

The primary cilium is a microtubule-based, non-motile organelle that extends as a solitary unit from the basal body (derived from the centrosomal mother centriole) of most cell types in the human body1.

Protozoans belonging to the phylum Ciliophora are covered with cilia, while flagella are a characteristic of the protozoan group Mastigophora. In eukaryotic cells, cilia and flagella contain the motor protein dynein and microtubules, which are composed of linear polymers of globular proteins called tubulin.

Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, whereas animal cells do not.