EVERYDAY SCIENCE

Detailed explanation-1: -Sponges exhibit a cellular level of organization. No structure can be considered an organ.

Detailed explanation-2: -Sponges are the only animals that lack true tissues. They only possess the cellular level of organization. Remember the levels of organization that make up the body of living organisms (cells-tissues-organs-organ systems-organism) from Biology I.

Detailed explanation-3: -Although sponges do not have organized tissue, they depend on specialized cells, such as choanocytes, porocytes, amoebocytes, and pinacocytes, for specialized functions within their bodies.

Detailed explanation-4: -Sponges are the most basic form of a multicellular animal. They lack the nerves and digestive systems seen in other animals, relying on water flow through their canal system for their food and oxygen.

Detailed explanation-5: -The sponge species Aplysina aerophoba. Sponges do not have organs or true tissues, however, they do have specialized cells that can carry out distinct functions within the organism. This is generally referred to as cellular-level organization.