Question

1. how do the choanocytes, ostia, porocytes, amoebocytes, and osculum work together for a sponge to feed? be sure to mention the role of each cell or structure and answer in the proper order that each structure does their job.
2. a sponge is described as “a sheet of cells over a frame.” what structures discussed compose the “sheet of cells?” what structures discussed compose the “frame?”
3. list four ways that a certain yellow sponge featured on a certain tv show was structurally incorrect based upon what was discussed today.

Explanation:

1. Role in feeding: Porocytes form channels (ostia) that allow water entry. Water brings in food particles. Choanocytes have flagella that create a current to move water through the sponge and trap food with their collar - like structures. Amoebocytes pick up the trapped food from choanocytes and distribute nutrients throughout the sponge. The osculum is the exit point for water, which has had food removed.
2. Sheet of cells: Choanocytes, amoebocytes, and other cell types form the sheet of cells. Frame: Spicules (calcareous or siliceous structures) and spongin (a protein - like material) compose the frame.
3. Structural inaccuracies: Real sponges are sessile and do not move around like the TV - show sponge. They do not have a face with eyes, nose, and mouth as in the TV show. They lack a complex nervous system as depicted. Real sponges do not have limbs for movement.

Answer:

1. Porocytes form ostia for water entry. Choanocytes create water current and trap food. Amoebocytes distribute nutrients. Osculum is the water - exit point.
2. Sheet of cells: Choanocytes, amoebocytes etc. Frame: Spicules and spongin.
3. Lack of sessility, no complex face features, no nervous system, no limbs.