Question

The most likely ancestors of chordates are considered to be echinoderms because:

• A. tunicates are echinoderms .
• B. there is a direct lineage from sea stars to tunicates
• C. embryos of some echinoderms are similar to primitive chordate embryos
• D. all of the above are correct

Answer 1

The correct option is C embryos of some echinoderms are similar to primitive chordate embryos

Chordates are coelomate deuterostomes, and probably share a common ancestor with echinoderms. Three important characteristics unite the Phylum Chordata. At some point in their life cycle, (primitive chordate embryos) all chordates have a notochord, a dorsal hollow nerve cord, and pharyngeal gill slits.

So, the correct option is, 'embryos of some echinoderms are similar to primitive chordate embryos'.