Question

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.

Answer 1

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.