(N/A) Symmetry in animals refers to the arrangement of body parts around a central axis or plane. It is classified into three main types:
$1$. Asymmetry: Animals are considered asymmetrical if any plane passing through the center of the body does not divide them into two equal halves. Example: $Sponges$.
$2$. Radial Symmetry: When any plane passing through the central axis of the body divides the organism into two identical halves, it is called radial symmetry. This is common in coelenterates, ctenophores, and echinoderms. Example: $Hydra$, $Starfish$.
$3$. Bilateral Symmetry: When the body can be divided into identical left and right halves only through a single plane, it is called bilateral symmetry. This is observed in annelids, arthropods, and chordates. Example: $Humans$, $Earthworm$.