Question

Select all that apply.

All animals, except for _____, develop as a protostome.

sponges
mollusks
arthropods
echinoderms
vertebrates
chordates

Answer 1

Sponges, echinoderms, vertebrates, and chordates are not Protostome.

Answer 2

Answer: Sponges, echinoderms, vertebrates, and chordates.

Protosome is the clade or group of animals in which the first opening in the embryo becomes the mouth. It represents all those animals that have a true body cavity and which share common ancestry. They include annelids, mollusks and arthropods. Sponges, echinoderms, vertebrates, and chordates do not develop as a protosome.