Which taxonomic group includes segmented worms such as bristle worms?

Which taxonomic group includes segmented worms such as bristle worms?

• A. Polychaeta
• B. Polyp
• C. Porifera
• D. Radial Symmetry

Answer: (A)

Bristle worms are Polychaeta, a class of the phylum Annelida. The key feature here is segmentation with bristle-like bristles, or chaetae, on most body segments and often paired limb-like structures called parapodia that aid in movement and gas exchange. This combination—many segments with chaetae—is what defines polychaetes and sets them apart from other groups. The other options aren’t taxonomic groups of segmented worms: a polyp is a life stage or form of Cnidaria and not segmented; Porifera are sponges with no true tissues or segmentation; radial symmetry describes a body plan rather than a taxonomic group, so it doesn’t identify a worm class.

Bristle worms are Polychaeta, a class of the phylum Annelida. The key feature here is segmentation with bristle-like bristles, or chaetae, on most body segments and often paired limb-like structures called parapodia that aid in movement and gas exchange. This combination—many segments with chaetae—is what defines polychaetes and sets them apart from other groups.

The other options aren’t taxonomic groups of segmented worms: a polyp is a life stage or form of Cnidaria and not segmented; Porifera are sponges with no true tissues or segmentation; radial symmetry describes a body plan rather than a taxonomic group, so it doesn’t identify a worm class.