Question

In animals: 1. Presence or absence of a cavity between the body wall and the gut wall is not important in classification. 2. The body cavity, which is lined by mesoderm is called coelom.

Answer 1

Option 2 is correct.

1) presence of coelom is one of the important character considered in classification.

2) true coelem have three fully deferrentiated layers including mesoderm. In pseudocoelomates it is present as mesoglea.