Thin atmosphere with low oxygen and carbon dioxide levels
They do not produce d.seeds
Answer:
A group of parasites called myxozoans have traditionally been considered simple multicellular protists. However, because these organisms possess stinging cells, some scientists consider them to be animals in the phylum that is named for such cells, the <u>cnidarians</u>.
Explanation:
Cnidarians are animals with radial symmetry, that is, their bodies can be divided, by different planes, into equal parts. It includes hydras, jellyfish, anemones and marine corals. Its body is a kind of sac with an opening (the mouth) surrounded by a circle of tentacles. Some have a dominant jellyfish phase, others polyp, or both. They present defensive nematocysts with stinging action.
