The principal characteristic that determines whether an aquatic ecosystem is classified as marine or freshwater is a. surface area b. water depth c. temperature d. salinity

The question is the principal characteristic that determines whether an aquatic ecosystem is described as a marine or fresh water is - the correct option is salinity. Salinity is defined as the concentration of salt in a water body. The salt concentration is used to determine whether the water is classified as fresh water or salt water. Marine salinity is about three point five percent, therefore, it is classified as salt water.

1. true.2. true.3. true.4. false.5. true.the concept of darwin's theory of evolution involves the idea that there are limited resources in a given living environment and that the organisms which live within have variations in their genetic make up due to random mating. the ones with beneficial genetic variations can express certain traits which give them an upper hand in surviving and reproducing in the said environment compared to ones who may have a more disadvantageous variation in traits. over time, the organisms with an upper hand will survive and reproduce more frequently and pass on their beneficial genes while the others die. the result is evolution, where we observe (usually, but not always) eventually, phenotypic distinct changes.

The light is great source of energy