Final answer:
The statement is false as bilateral symmetry refers to an animal that can be divided into mirror-image halves, not a circular formation. It features a head and a tail, a dorsal and ventral side, and allows for active and directional motion.
Step-by-step explanation:
Understanding Bilateral Symmetry
The statement that in bilateral symmetry the animal is organized in a circular formation is false. Bilateral symmetry refers to a type of symmetry in which an animal can be divided down its length into mirror-image halves, with a distinct head (anterior) and tail (posterior), along with dorsal (back) and ventral (belly) sides. Unlike radial symmetry, which exhibits a circular formation around a central axis, bilateral symmetry exhibits two similar halves with a defined left and right side. This body plan is associated with cephalization, a condition where sensory organs and nerve tissues are concentrated at the frontal end of the body, promoting active and directional movement. Examples of bilaterally symmetrical animals include humans, crabs, and butterflies.
Bilateral symmetry differs significantly from radial symmetry, which is found in stationary or slow-moving aquatic animals like jellyfish and sea anemones. These creatures have body plans that can be divided into similar halves through multiple planes passing through the organism's axis. Furthermore, while radial symmetry is associated with diploblasts, bilateral symmetry is generally seen in animals classified as triploblasts that develop three primary germ layers during embryogenesis.