Which type of animal is a basal organism that lacks true tissue and acts as an aquatic suspension feeder?

Sponges are classified as basal organisms primarily because they are among the earliest forms of multicellular life and lack true tissues and organs that are characteristic of more complex animals. This simplicity in structure is reflected in their body design, which consists of a porous body and a system of canals that allows water to flow through them. They possess specialized cells called choanocytes that help in the filtration of water, trapping food particles as they feed by suspending themselves in the water column. This method of feeding is known as suspension feeding.

Sponges generally inhabit aquatic environments, usually in marine settings, though some species can be found in freshwater. Their ability to filter large volumes of water makes them crucial to their ecosystems, contributing to water clarity and nutrient cycling.

Other options such as jellyfish, coral, and echinoderms are more complex organisms that possess true tissues and specific body structures, thus distinguishing them from sponges. Jellyfish, for example, belong to the phylum Cnidaria, which has specialized tissue layers and a nerve net for processing information. Coral, also part of Cnidaria, have a skeleton and form symbiotic relationships with other organisms, thus representing a higher level of complexity. Echinoderms, which include starfish and sea