Question

1. While exploring the ocean you find a new organism attached to the sea floor. It is about half a meter across, has a round shape, and is not soft to the touch.

A. Describe two ways you could tell if the organism is a member of the Porifera or Anthozoa, just by looking at it. (2 pts)

B. Compare and contrast the process of how Porifera and Cnidarians collect and digest their food.

Answer 1

A.

Porifera	cnideria
Mostly assymetrical	Radially symmetrical
Bioluminescence absent pores present on body.	Bioluminescence present pores absent

B.

Porifera

cnideria

have a water transport or canal system. Water enters through minute pores (ostia) in the body wall into a central cavity, spongocoel, from where it goes out through the osculum. This pathway of water transport is helpful in food gathering digestion is intracellular. filter-feeders meaning their food enters with water and they filter the food out. collar cells/choanocytes engulf and digest the food. Process: Digestion in sponges occurs when the flagella of choanocytes draws water through the holes in the body wall, then expels it through the osculum. Here, specialized collar cells trap food particles and digest them, or pass them on to an ameboid-like cell for digestion and circulation.

have a central gastro-vascular cavity with a single opening, mouth on hypostome. Digestion is extracellular and intracellular. carnivorous predators. They capture small animals using their nematocysts (stinging cells).They then use their tentacles to push food through their mouth into their gastrovascular cavity Process: cniderians  do not have a true digestive system. Food enters their gastrovascular cavity via mouth and extracellular digestion enzymes are secreted into their gastrovascular cavity. Cells lining the cavity absorb the digested nutrients and smaller food particles.