Question

question 4
serial repetition of segments is a defining characteristic of which worm phylum?
○ flatworms
○ segmentation is not a defining characteristic of any of the worm phyla.
○ annelids
○ roundworms

Explanation:

Annelids, like earthworms, have a body plan with serial repetition of segments (metamerism). Flatworms (Platyhelminthes) have a flattened body without true segmentation. Roundworms (Nematoda) have a cylindrical body but lack the distinct serial segmentation. Since annelids are defined by this characteristic, the answer is annelids.

Answer:

Annelids