Final answer:
Porifera are multicellular marine animals that are part of the phylum Porifera, characterized by their lack of true tissues and functioning as filter feeders. A commercial sponge can be synthetic or a processed natural sponge, used for cleaning purposes.
Step-by-step explanation:
To compare a porifera to a commercial sponge, option B and option C are both correct. Porifera is indeed a multicellular marine animal, and a commercial sponge can refer either to a synthetic cleaning tool made by humans or sometimes to natural sponge material harvested from the sea but processed for use in households.
Porifera, belonging to the phylum of the same name, are simple aquatic invertebrates that lack true tissues and body symmetry. They are known for their specialized cells and an endoskeleton made up of spicules and spongin fibers, which contribute to a structured yet simple biological form. Sponges function primarily as filter feeders, drawing water through their porous bodies to capture food particles. They exhibit various specialized cells such as pinacocytes, amoebocytes, and sclerocytes, however, these do not form true interconnected tissues.
In contrast, a commercial sponge may be synthetic, created from materials such as cellulose or plastic polymers, designed to absorb water and clean surfaces. Natural commercial sponges, on the other hand, are typically harvested from the ocean but are no longer living organisms and have often been treated for human use.