In the northwestern portion of the United States, salmon runs from the ocean to the freshwater rivers are extremely important. Salmon carry rich nutrients only found in the ocean and deposit them into the rivers. These nutrients are then distributed to the nearby forests as birds, bears, and other animals consume the salmon or the salmon eggs. Human activities have caused a decrease in native salmon species. Formulate a hypothesis regarding the impact this decrease will cause within the local ecosystem.

Kelly ran electricity though a sample of water using electrolysis. the water changed into two gases, x and y. it was not possible to break down the gases x and y into simpler particles.

1. variations in a population of moths allow for some of its members to be able to adapt to environmental changes. the better adapted of the moths will be able to survive the change and thus prevail as the “fittest” of the species. (a) describe three mechanisms in which variation can occur within a species population. (b) explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. justify your answer.

The sketch shows a rynchosaur, an extinct animal that is known only from fossils. there has been much debate about the classification of these creatures. some scientists suggest that they belong with primitive amphibians, and some think they are related to snakes and lizards. the data equally support both cases. which statement best explains how to draw a cladogram that includes the rynchosaur? draw the cladogram for amphibians. draw the cladogram for reptiles. draw two cladograms, both showing the traits, and leave it as a hypothesis. draw two cladograms, both showing the traits, and have scientists vote