Question

Problem 5:

a. What do you think is the evolutionary advantage of having a celom?

b. Describe the main differences between protonephridia and metanephridia.

Answer 1

Answer a ) The evolutionary advantage of having is coelom (a apace formed between ectoderm and endoderm) is :

1) They have the advantage of having a good circulatory system as without a coelom there will be more of the body mass which adds stress and weight to the body.

2) Removal of waste products from the body is also advantageous in these organisms.

3) Aids in the easy movement of the organism from one place to another.

Answer b ) Protonephridia have flame cells

while MEtanephridia have funnel cells known as nephridospore

Both the flame cells and nephridospore are used for excretion in the organism.

Metanephrodia also has two openings in their cells unlike protonehridia whch have a single opening and a blind sac.

Protonephridias include groups like Nematodes, Platyhelminthes etc

while Metanephridia includes Molluscas and Annelids and Arthropods.

i hope i was able to help you with the answers ! :)