NEET BIOLOGY

Detailed explanation-1: -Only members of the phylum Porifera (sponges) have no body plan symmetry. There are some fish species, such as flounder, that lack symmetry as adults.

Detailed explanation-2: -Importantly, she notes, not all animals are bilaterally symmetrical. Some animals have radial symmetry with four or five axes, like starfish, jellyfish and sea urchins. The only creature on Earth who is not symmetrical in any way is the sponge.

Detailed explanation-3: -Phylum Porifera (sponges): Aquatic animals with radial symmetry or irregular shapes.

Detailed explanation-4: -Porifera is mostly asymmetrical. Asymmetrical means that any plane traveling through the body’s central axis does not divide the organism into two equal halves.

Detailed explanation-5: -Sponges of class Demospongiae have mostly asymmetrical sponges. The correct answer is Demospongiae. Some examples of Demospongiae are cliona, chalina, euspongia, oscarella, etc. These are sponges with soft bodies that cover a hard massive skeleton.