4 Written questions
3 Multiple choice questions
- The sponge body is comprised of a couple different cell types that form the outside and inside layers of the body wall.
- Extracellular protein fibers give structure and strength to the sponge body and spicules, spines made of silica or calcium carbonate, offer protection from predation.
- In simple sponges, water enter the body through pores in the walls called ostia and passes into the spongocoel, a central space lined with choanocytes where food particles are trapped and digested intracellulary. Nutrients are passed to neighboring cells. Water leaves through a hole at the top of the sponge called the osculum. In more complex body plans, there is no spongocoel but several smaller chambers lined with choanocytes
3 True/False questions
What kind of feeding? → intracellular
where does gas exchange occur? → They lack tissues, organs, and organ system.
• Type of body cavity → no true tissue