AP BIOLOGY

Detailed explanation-1: -Adult echinoderms are radially symmetrical, i.e., they can be cut into two equal halves along more than one plane. More specifically, they are pentaradially symmetrical. However, the larvae are bilaterally symmetrical .

Detailed explanation-2: -Radial Symmetry: Unlike chordates, like humans or sharks, echinoderms possess a radially symmetrical body plan. In almost all situations involving echinoderms, the species exhibits pentamerous radial symmetry (pentaradial), or five sided radial symmetry.

Detailed explanation-3: -Pentaradial symmetry is a type of radial symmetry, which is a characteristic of echinoderms, in which body parts are arranged along five rays of symmetry. It means the organism is in five parts around a central axis.

Detailed explanation-4: -One characteristic of an echinoderm is that they all have pentamerous radial symmetry. This simply means they all have 5 equal body parts. You can divide these animals into five equal parts, and every part is the same. For example, most sea stars have five arms or a multiple of five arms.

Detailed explanation-5: -Echinoderms are a phylum exclusively consisting of marine animals. The adults are recognizable by their radial symmetry whereas their larvae are bilaterally symmetrical.