LOCOMOTION AND MOVEMENT

Movement is a fundamental characteristic of living organisms. Plants exhibit diverse movements—tropisms (directional responses to stimuli) and nastic movements (non-directional responses)—but animals display voluntary movements enabling locomotion. Movement occurs at multiple levels: molecular movements (enzyme action), organellar movements (ciliary/flagellar beating), cellular movements (cell migration), and organismal movements (walking, running, flying, swimming).

Locomotion—the movement of an organism from one place to another—requires coordinated activity of muscles, bones, and nervous system. Whether humans walk upright, birds fly, fish swim, or insects crawl, the underlying principles of muscle contraction and skeletal mechanics remain fundamentally similar.