Which choice best describes an independent variable in a scientific investigation? An independent variable is the one variable changed and tested by a scientist in a scientific investigation. An independent variable is an educated guess that a scientist makes after observing something interesting. An independent variable is one part of the hypothesis a scientist writes prior to beginning a scientific investigation. An independent variable is the fastest way to measure the success of a scientific investigation.

i think that it is c, d, and e, hope this

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.

other quantities, called derived quantities, are defined in terms of the seven base quantities via a system of quantity equations. the si derived unitsfor these derived quantities are obtained from these equations and the seven si base units.