Question

Radial symmetry is NOT found in adults of phylum ______.

• A. Hemichordata
• B. Coelenterata
• C. Echinodermata
• D. Ctenophora

Answer 1

The Correct Option is A

In biology, symmetry refers to the arrangement of body parts around a central axis. Radial symmetry is a type of symmetry where body parts are arranged around a central point, like spokes on a wheel. This form of symmetry is common in certain animal phyla, mainly those in aquatic environments.

Let's examine the phyla mentioned in the options to determine which one does not exhibit radial symmetry in adults:

1. Hemichordata: Members of this phylum, such as acorn worms, exhibit bilateral symmetry in their adult forms, not radial symmetry.
2. Coelenterata: This term often refers to Cnidaria, which includes jellyfish and corals, known for their radial symmetry.
3. Echinodermata: This group includes starfish and sea urchins, which show radial symmetry as adults.
4. Ctenophora: Also known as comb jellies, these organisms are characterized by their radial symmetry.

Based on this analysis, radial symmetry is NOT found in adults of the phylum Hemichordata.