Why are sponges considered unique in the evolution of animals? - Quora
Animals Flashcards | Quizlet
Phylum Porifera Sponges are the simplest of all animals; best described as aggregations of specialized cells Sponges do not have true tissues or organs; - ppt download
Which group of organisms has the derived characteristics of true tissues, bilateral symmetry, and a - brainly.com
Tissues of the Human Body - Advanced | CK-12 Foundation