Which of the following is not a characteristic of cnidarians?

Question

They are diploblastic, they are radially symmetric, they are deuterostomes. or there are two basic body plans; they are either a polyp, a medusa, or both.

 

Answer 1

Answer: *Cnidarians are NOT deuterostomes.

Explanation:

Cnidarians include Hydrozoa (tiny freshwater and marine invertebrates), Cubozoa (such as Box Jellyfish), Scyphozoa (like Jellyfish), and Anthozoa (includes sea anemones and coral). All cnidarians share a unique trait: stinging nematocysts attached to tentacles.

*Cnidarians are diploblastic (Their body wall tissues are composed of only two layers: ectoderm and

endoderm; They lack the middle layer, mesoderm found in higher organisms).

*Cnidarians do have radial symmetry (They have body symmetry around a central axis).

*Cnidarians do have two basic body forms: Polyps (many cnidarians have an asexual reproductive body form called an asessile polyp) and Medusa(e) (A free-floating/swimming form that reproduces sexually). However, some cnidarians, such as Sea Anemones, lack free-floating body forms, and simply release polyps to reproduce.

*Cnidarians are NOT deuterostomes. Deuterosomes include: Chordata (vertebrates, etc.); chinodermata (sea urchins, starfish, sea cucumbers); and Hemichordata (acorn worms and related);

Cnidarians are not protostomes, either. Protostomes include: arthropods (crabs, crayfish,etc.), annelids (earthworms, leeches, etc.), and molluscs (including squid, octopus, snails, slugs).

-Animals such as Cnidarians and Ctenophores (Comb Jellies) are classified in the group of animals having radial symmetry, this group is called "Radiata."

-Animals with bilateral symmetry are classified in the group called "Bilateria." Bilateria includes both deuterostomes and protostomes.