The Living World 6th Edition by George Johnson, Jonathan Losos,William Ober,Claire Garrison

تمرين 22

Echinoderms begin life as free-swimming larvae with bilateral symmetry and then become adults with radial symmetry. Some biologists explain this change in symmetry as a change in form appropriate for
A) an animal traveling through the environment to a form more appropriate to a sessile lifestyle.
B) an animal with a sessile lifestyle to a form more appropriate to traveling through the environment.
C) a predator to a form more appropriate to a filter-feeder.
D) an animal living in freshwater to a form more appropriate to an animal living in a marine environment.