NEET BIOLOGY

Detailed explanation-1: -They are generally marine aquatic organisms, with a few freshwater species. Their bodies are asymmetrical. Body shape can be cylindrical, vase-like, rounded or sac-like. They are diploblastic animals with two layers, the outer dermal layer and the inner gastral layer.

Detailed explanation-2: -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-3: -Only sponges (phylum Porifera) have asymmetrical body plans. Some animals start life with one type of body symmetry, but develop a different type as adults; for example, sea stars are classified as bilaterally symmetrical even though their adult forms are radially symmetrical.

Detailed explanation-4: -Characteristics of Phylum Porifera Only a few are found in freshwater. They are either radially symmetrical or asymmetrical. Their body is usually cylindrical. The scleroblast secretes spicules while spongin fibres are secreted by spongioblasts.

Detailed explanation-5: -Sponges are multicellular animals, unique in many ways. They are the only group of animals that can be classified as asymmetric, which means they possess no symmetry at all. There is no plane through their bodies where you could cut them in half to produce two mirror images.