In museum study, a juvenile roundworm increases in size by shedding its old cuticle several times. The specimen or feature is best linked with:

Ecdysis is molting of the outer cuticle. Nematodes and arthropods both molt, which is one reason they are grouped among ecdysozoan animals in modern phylogeny. This MCQ belongs to the Nematoda topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.