An avid naturalist diver has decided to vacation on a remote island, possibly never visitedby a human before, with a rocky intertidal zone. while out exploring he comes across what looks like a jellyfish but has bilateral symmetry. he considers what he knows of the simple phylogeny of animals. he would like to place this species into the group bilateria. name one other characteristic that would lend support to his placing this organism in the group bilateria. a)the presence of collagen in its tissues. b)the presence of an oral cavity. c)the presence of digestive tissues. d)the presence of three different tissue layers.

D) the presence of three different tissue layers.

Explanation:

Animals belonging to the group Bilateria have bilateral symmetry during embryonic phase. Being bilateral means that the embryo can be divided into symmetrical right and left parts which are mirror images of each other. Most of them remain bilateral even as adults except echinoderms.

Bilateral embryos have three germ or tissue layers: endoderm, mesoderm and ectoderm. These layers give rise to all the body parts. Digestive tract is well developed in majority of them except for few phyla. Some of them are acoelomates which means that they do not have a body cavity while some are coelomates.

So one characteristic which will surely be present in a bilateria would be the presence of three tissue layers hence it can be used to lend support to his placing the particular organism in the group.

a

explanation: