What is the main basis for placing the arthropods and nematodes in Ecdysozoa in one hypothesis of animal phylogeny?
-Animals in both groups are segmented.
- Animals in both groups undergo ecdysis.
-They both have radial, determinate cleavage, and their embryonic development is similar.
-Fossils reveal a common ancestor of the two phyla.
-Analysis of genes shows that their sequences are quite similar, and these sequences differ from those of the lophotrochozoans and deuterostomes.