Question

The evolutionary process where segments combine to form distinct and functional units is known as ___________

• A. Regeneration
• B. Segmentation
• C. Cephalisation
• D. Tagmosis

Answer 1

The correct option is D

Tagmosis

Tagmosis is the evolutionary process where segments in animals combine to form distinct and functional units. A tagma (plural: tagmata) is a specialised grouping of multiple segments or metameres into a coherently functional morphological unit. Familiar examples are the head, the thorax, and the abdomen of insects. The metameres within a tagma may be either fused (such as in the head of an insect or a mammal) or so jointed as to be independently moveable (such as in the abdomen of most insects).