A dependent variable is how they are recording, measuring or keeping track of the science experiment their doing.
A independent variable is the things/types there using to compare what is the most/least affective in the experiment.
A controlled variable is something that stays the same in the experiment or a group/set used for comparison
They help with storing "food" in fruits and foods to make them edible for us people.
The original source of phosphorus in a terrestrial ecosystem is soil microorganisms. soil becomes deficient in phosphorous leading to ecosystem retrogression. phosphorous can be found in our body, it builds strong bones and teeth.
hope it helps!
