AP BIOLOGY

Detailed explanation-1: -The phylum Porifera comprises the sponges. Sponges are simple invertebrate animals that live in aquatic habitats. Although the majority of sponges are marine, some species live in freshwater lakes and streams. They are found in shallow ocean environments to depths as great as five kilometers (km).

Detailed explanation-2: -The Porifera are primarily filter feeders, utilizing food particles suspended in the water and captured by the choanocytes. Food particles consist essentially of bacteria, other microorganisms, and particles of organic debris; sponges also probably absorb dissolved organic substances.

Detailed explanation-3: -In order obtain food, sponges pass water through their bodies in a process known as filter-feeding. Water is drawn into the sponge through tiny holes called incurrent pores.

Detailed explanation-4: -Sponges (Poriferans) receive (incoming) food particles with the help of collar cells (choanocytes). These collar cells or choanocytes are surrounded by microvilli which filter the incoming food particles. Therefore, sponges/Poriferans are called filter feeders.

Detailed explanation-5: -Sponges are a type of suspension feeder, but because they actively pump water through their bodies, they are more specifically called filter feeders.