Question

The higher invertebrates are divided into two evolutionary lines, protostomes and deuterostomes. This division is based on which developmental feature?

Answer 1

A) whether the blastopore ultilmately developes into a mouth or an anus
B)Whether the embryonic cells undergo spiral or radial cleavage
C) Whether the coelom forms by splitting the mesoderm or through the pocket of the gut

Answer 2

the first opening developing during embryonic development becomes the anus, while in protostomes the first opening becomes the mouth.

Answer 3

thanx