AP BIOLOGY

Detailed explanation-1: -The unique digestive system of cnidaria consists of a single cavity known as the gastrovascular cavity or coelenteron, which is the place where food is digested. The single opening of this cavity serves as both the mouth and anus of this digestive system, through which food is both ingested and excreted.

Detailed explanation-2: -Cnidarians take in food through their mouths, which is then digested in the coelenteron. Nutrients are then passed to other areas of the body for use, and waste products are expelled either through the mouth or through surface cells via water circulation.

Detailed explanation-3: -Most cnidarians are marine and all are carnivorous. They have tissues but no organs and their digestive cavity has one opening which serves as both their mouth and anus.

Detailed explanation-4: -Much like the echinoderms and sponges, cnidarians have no excretory organ. An excretion process by simple diffusion through the surface of the body means that the composition of body fluids of the cnidarian animal will influence the diffusion of wastes.

Detailed explanation-5: -Cnidarians have no well-defined separate respiratory, circulatory, or excretory organs; their tissues, composed of two cell layers, surround a cavity known as a coelenteron (gastrovascular cavity), which is the basic internal organ. Tentacles surrounding the mouth are used to capture and ingest food.