Expressed in the midline of all animals possessing bilateral symmetry, they can act as long or short range signals during neurogenesis.

The latter two choices are more convenient for solving problems which possess cylindrical or spherical symmetry respectively.

Other physical features include being ectothermic, possessing bilateral symmetry, and polymorphic.

One seeming exception is the starfish and their relatives, for these possess radial symmetry.

Hydra is a genus of simple fresh-water animal possessing radial symmetry.

Triploblastic organisms generally possess bilateral symmetry, which is where the clade Bilateria takes its name.

In practice however the beam is not uniform and does not possess perfect cylindrical symmetry.

Kimberella may show a similarity to molluscs, and other organisms have been thought to possess bilateral symmetry, although this is controversial.

An optical system is considered rotationally symmetric if it possesses rotational symmetry when unfolded.

One is an irregular dodecahedron with pentagonal faces, possessing tetrahedral symmetry (T).