Which of the following groups is the correct classification for roundworms?

Which of the following groups is the correct classification for roundworms?

• A. Trematode
• B. Cestode
• C. Acanthocephalan
• D. Nematode

Answer: (D)

Roundworms are nematodes, a distinct phylum of worms that are long, slender, and unsegmented with a protective cuticle and a pseudocoelom acting as a hydrostatic skeleton. They have a complete digestive tract from mouth to anus and typically separate sexes. This body plan sets them apart from the other groups: trematodes and cestodes are flatworms (phatyhelminthes) with leaf-like shapes, and cestodes are segmented; acanthocephalans have a unique thorny proboscis. Because of these anatomical and developmental differences, the correct classification for roundworms is nematodes. Examples you might encounter include Ascaris and Enterobius, both nematodes.

Roundworms are nematodes, a distinct phylum of worms that are long, slender, and unsegmented with a protective cuticle and a pseudocoelom acting as a hydrostatic skeleton. They have a complete digestive tract from mouth to anus and typically separate sexes. This body plan sets them apart from the other groups: trematodes and cestodes are flatworms (phatyhelminthes) with leaf-like shapes, and cestodes are segmented; acanthocephalans have a unique thorny proboscis. Because of these anatomical and developmental differences, the correct classification for roundworms is nematodes. Examples you might encounter include Ascaris and Enterobius, both nematodes.