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.
The main abiotic limiting factors are the availability of water and light and the availability of shelter. The main limiting biotic factors are population density and inharmonious (negative) ecological interactions (competition, predatism, parasitism, ammensalism).