EVERYDAY SCIENCE

Detailed explanation-1: -Bilateral symmetry involves the division of the animal through a sagittal plane, resulting in two mirror image, right and left halves, such as those of a butterfly (Figure 3), crab, or human body. Animals with bilateral symmetry have a “head” and “tail” (anterior vs. posterior), front and back (dorsal vs.

Detailed explanation-2: -Thus, only one plane of symmetry will divide a bilateral animal into symmetrical halves, the median longitudinal, or sagittal, plane.

Detailed explanation-3: -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-4: -Bilateral symmetry is characteristic of the vast majority of animals, including insects, fishes, amphibians, reptiles, birds, mammals, and most crustaceans.

Detailed explanation-5: -The two main types of symmetry are radial symmetry (in which body parts are arranged around a central axis) and bilateral symmetry (in which organisms can be divided into two near-identical halves along a single plane). A few organisms display asymmetry, meaning they have no body plane symmetry at all.