Semiconservative replication was not the only model of DNA replication proposed during the mid-1950s, however. In fact, two other prominent hypotheses were put also forth: conservative replication and dispersive replication.
Main idea. Aquatic ecosystems are grouped based on abiotic factors such as water flow, depth,distance from shore, salinity, and latitude. Freshwater ecosystems. The major freshwater ecosystems include ponds, lakes, streams,rivers, and wetlands.
Abiotic and Biotic Factors in an Ecosystem. An ecosystem consists of the biological community of living organisms (biotic) and non-living organisms (abiotic) that occurs in a specific locale, and the physical and chemical factors that make up the environment.