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.
A Guide to the Cnidarians. 1  01. of 10. Basic Anatomy. 2  02. of 10. Radial Symmetry. 3  03. of 10. Life Cycle - Medusa Stage. 4  04. of 10. Life Cycle - Polyp Stage. 5  05. of 10. Cnidocyte Organelles. 6  06. of 10. Diet and Eating Habits. 7  07. of 10. Jellyfish Facts and Classification. 8  08. of 10. Coral Facts and Classification. 9  09. of 10.