The controlled variable is an element that is not changed throughout an experiment, because it’s unchanging state allows the relationship between the other variables being tested to be better understood.
It has a job similar to a police officer who allows select people to enter and leave a crime scene.
Explanation:
The primary purpose of the cell membrane is to preserve the cell from its surroundings. The cell membrane manages the movement of materials in and out of cells and organelles. In this form, it is selectively perforable to ions and organic molecules. It is the same as of police officer or security guard that check the people and allow only a few to enter a specific place.
Answer:
Through the process of Anthropogenic additions of N and P to the fresh water system can provide a strongest evidence for the above mentioned hypothesis.
Explanation:
As phosphorus is less mobile than nitrogen compounds, it is less likely to be found in fresh water where the organisms fail to access it. Phosphorus bounds mostly in the terrestrial ecosystem and in the aquatic matters because it has a sticky compound.
Thus it is a limited nutrient in freshwater lake like Mairead. However, this hypothesis can be different depending on other factors. Like, by adding anthropogenic N and P, this balance can be affected largely.