1. Answer the following questions in brief.
1. Name two cnidarians and two poriferans.
2. What are excretory structures present in segmented worms?
Answers
Answer:
a) Sponges- Ammonia is the chief excretory product in sponges. It diffuses from cells into the water filling the canals and surrounding the sponge. From the canal system, the waste matter is carried away by the outgoing water current.
b) Roundworms -No specific excretory organ is found. Roundworms diffuse metabolic waste through there body wall.
c) Annelids- The excretory system consists of nephridia as the excretory organ which is analogous to the kidney of vertebrates.
d) Crustaceans- two types of excretory organs are found i.e antennal glands and maxillary gland.
e) Insects-Malphigian tubules.
f) Flatworms-Nephridium.
g) Echinoderms-No specific organ, they use diffusion to get rid of there body's metabolic waste.
h) Cnidarians- No specific excretory organ. Metabolic waste diffuses from cells into the gastrovascular cavity and then it is released to outside through mouth.
i) Molluscs- Kidney like nephridia.
j) Vertebrates-Kidney, nephron is the structural and functional unit of the kidney.