Bilateral symmetry

/baɪˈlætərəl ˈsɪmətri/ noun

Definition

A body plan in which the left and right sides of an organism are mirror images of each other when divided along a central axis. This type of symmetry is characteristic of most animals, including humans.

Etymology

From Latin 'bi' (two) and 'latus' (side), combined with Greek 'symmetria' (measured together). The concept was formalized in biological terminology during the 18th century as scientists began systematically describing body plans.

Kelly Says

Bilateral symmetry was a game-changer in animal evolution because it allowed for the development of a distinct head end with concentrated sensory organs! This 'cephalization' enabled animals to move directionally and process information more efficiently than radially symmetric animals.

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