Question

1.) How is the digestive system of Cnidarians different from that of sponges?

2.) How can the testes and the ovaries on a hydra be distinguished from one another?

3.) How does the structure of these polyps (hydranths & gonangia) reflect their functions?

4.) List 3 differences between cnidarians and sponges?

5.) List differences between Cnidarians and Ctenophores?

Answer 1

Ans 1

Digestive system is different in sponges and cnidarians.

In sponges, food is internalised using phagocytosis process and then food particles are digested by individual cells.

In cnidarians, digestion is extracellular. Cnidarians release enzymes to break down food outside of body and then special cells of gastrovascular cavity absorb the nutrients.

Hence, major difference is that in sponges food is digested internally , but in cnidarians food is digest outside of body.