The Living World 8th Edition by George Johnson

تمرين 18

One difference between the pseudocoel found in the phylum Nematoda (roundworms) and the coelom found in the phylum Annelida (segmented worms) is that the pseudocoel develops between the mesoderm and the _____________ in roundworms, and the coelom develops within the _____________ in segmented worms.
A) ectoderm; mesoderm
B) endoderm; mesoderm
C) ectoderm; endoderm
D) endoderm; ectoderm