Question

which group of organisms has the derived characteristics of true tissues, bilateral symmetry, and a pseudocoelom?
sponges
roundworms
annelids
chordates

Explanation:

1. Analyze sponges: Sponges (Porifera) lack true tissues and have asymmetrical or radial symmetry, so they don't match.
2. Analyze roundworms: Roundworms (Nematoda) have true tissues, bilateral symmetry, and a pseudocoelom (a body cavity not completely lined by mesoderm), which matches the given characteristics.
3. Analyze annelids: Annelids have a true coelom (not pseudocoelom) and segmentation, so they don't match.
4. Analyze chordates: Chordates have a true coelom and other unique features (like notochord), so they don't match.

Answer:

roundworms (the option with "roundworms" text)