Mutations and rearrangements that occur by misalignment during DNA replication are frequent sources of genetic variation in bacteria. Dislocations between a replicating strand and its template at repetitive DNA sequences underlie the mechanism of these genetic events.
Cnidarians take on two basic forms, a medusa and a polyp. The medusa form is a free-swimming structure which consists of an umbrella-shaped body (called a bell), a fringe of tentacles that hang from the edge of the bell, a mouth opening located on the underside of the bell, and a gastrovascular cavity. The mesoglea layer of the medusa body wall is thick and jelly-like.
Share. By Laura Klappenbach. Cnidarians (Cnidaria) are a group of aquatic animals that includes jellyfish, corals, sea anemones, and hydras. The basic form of the cnidarian body is quite simple and consists of a gastrovascular cavity with a single opening through which food is ingested and waste is released.nidarians (Cnidaria) are a group of aquatic animals that includes jellyfish, corals, sea anemones, and hydras.