Blastopores...?

Question

What is the difference between a complete and an incomplete digestive system? The first opening that forms on an embryo is called a blastopore. When the blastopore develops into a mouth, what is the animal called? When the blastopore develops into an a**s, what is the animal called? What are some of the phyla belonging to each group?

Answer 1

An incomplete digestive system (found in certain lower invertebrates like hydra and starfish) is where a single opening to a pouch-like cavity serves as both mouth and a**s.

A complete digestive system (all insects have them) means that food processing occurs within a tube-like enclosure, the alimentary canal, running lengthwise through the body from mouth to a**s.

In protostome development, the first opening in development, the blastopore, becomes the animal's mouth.

Eg:-Platyhelminthes, rotifers

In deuterostome development, the blastopore becomes the animal's a**s.

Eg:-Fishes and Mammals

Best Wishes :)