Why are sponges and coelenterates called diploblastic animals?

What are the sponges?

Name a fresh water sponge. and a coelenterate

why are some bryophytes called liverworts?

Triploblastic animals are more complex than diploblastic animals. Do you agree with this statement? Justify.

Why are d block elements called transition elements?

Rabbit is called a coprophagous animal. Why?