1. An animal that has body parts that extend outward from its center shows

A) radial symmetry.

B) segmentation.

C) several planes of symmetry.

D) bilateral symmetry.

2. A coelom is a body cavity

A) completely lined with mesoderm.

B) partially lined with mesoderm.

C) without mesoderm.

D) partially lined with endoderm.

An animal that has body parts that extend outward from its center show radial symmetry. The body plans of echinoderms, ctenophores, cnidarians, and many sponges and sea anemones show radial symmetry. A coelom is a body cavity completely lined with mesoderm. The coelom exists in multicellular organisms. It is a fluid-filled body cavity that is completely lined by tissue created from the mesoderm.