EVERYDAY SCIENCE

Detailed explanation-1: -Bilaterally symmetrical animals have a dorsal side (top), a ventral side (bottom) and distinct left and right sides. They also have an anterior side (head), and a posterior side (tail), and exhibit cephalization.

Detailed explanation-2: -Examples of animals that possess bilateral symmetry are: flatworms, common worms ("ribbon worms"), clams, snails, octopuses, crustaceans, insects, spiders, brachiopods, sea stars, sea urchins, and vertebrates.

Detailed explanation-3: -Animals with radial symmetry have many lines of symmetry. Because of the circular arrangement of their parts, radially symmetrical animals do not have distinct front or back ends. They may have distinct top and bottom sides.

Detailed explanation-4: -When the body plan of an animal can be divided along a line that separates the animal’s body into right and left halves that are nearly identical of each other, it is said to have bilateral symmetry.

Detailed explanation-5: -Limbs and sense organs are in bilaterally symmetrical pairs, dictating a high degree of symmetry in the brain itself.