What is a feature of adult echinoderms that is similar to more primitive groups?Group of answer choicesno anusno nervous systemno coleumradial symmetry

Breakdown the Problem

1. Identify the features of adult echinoderms.
2. Compare these features with more primitive groups of animals.

Relevant Concepts

• Echinoderms exhibit certain characteristics, such as radial symmetry and a water vascular system.
• Primitive groups may include organisms like cnidarians or worms that exhibit simpler structures.

Analysis and Detail

Echinoderms:

• Have radial symmetry, which allows them to have an organized body plan around a central axis.
• They possess a complex water vascular system and a coelom.

Primitive Groups:

• Cnidarians (like jellyfish) exhibit radial symmetry and no true nervous system.
• Flatworms and similar organisms may show bilateral symmetry but lack a complete digestive system (no anus) in certain types.

Verify and Summarize

From the options provided, the feature that relates adult echinoderms to more primitive groups is radial symmetry. Primitive groups also display radial symmetry, though other features such as the absence of an anus or a nervous system do not apply universally and do not serve as a robust comparison.

Final Answer

The feature of adult echinoderms that is similar to more primitive groups is radial symmetry.