For semester exam preparation, consider this situation: a modern phylogeny groups insects and nematodes together more closely than older body-cavity classifications suggested. The correct conclusion is:

Arthropods and nematodes are ecdysozoans because both molt a cuticle. This molecular and developmental grouping differs from older schemes based mainly on coelom type. This MCQ belongs to the Comparative zoology topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.