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: -Cephalization is an evolutionary trend in which, over many generations, the mouth, sense organs, and nerve ganglia become concentrated at the front end of an animal, producing a head region. This is associated with movement and bilateral symmetry, such that the animal has a definite head end.

Detailed explanation-3: -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-4: -Complete answer: The bilateral symmetry is present in most of the animals. In this kind of symmetry, the line divides the body into two equal halves. The right and left sides of the body are exactly the mirror image of each other.