Answer: Option B
Explanation:
Usually in scientific experiments, at least one parameter is checked; here, the growth rate of wheat in two different conditions is being evaluated.
Hence, growth rate of wheat alone in pans A, B and C becomes the standard or referential control against which the experimental control (Wheat + clover) in pans D, E and F is evaluated, since both treatments are exposed to the same external conditions.
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The word is scientifically termed as Peristalsis.
This is an example of Human Genome Project. It was a global logical research extend with the objective of deciding the arrangement of nucleotide base matches that make up human DNA, and of recognizing and mapping the greater part of the qualities of the human genome from both a physical and a practical point of view.