The lack or absence of symmetry
In biology, the body plan of many organisms exhibit symmetry. Although the parts in a dividing plane or around an axis are not exactly the same, there is a significant correspondence in form, size, distribution, or arrangement of parts. Symmetry is observed particularly with regard to the external appearance of organisms. Bilateral organisms exhibit similarities between left and right sides. Radially symmetrical organisms have body plan in which every side is the same around an axis. In contrast, there are organisms lacking external symmetry. Flounders (adult form where both eyes are on one side) and hermit crabs (having a large claw on one side) are examples of organisms exhibiting asymmetry.