I believe it's more specialized than an amoeba
Microscopic processes are related to absorption, digestion, metabolism and excretion. Molecular or microscopic processes are related to the balance of elements such as enzymes, vitamins, minerals, amino acids, glucose, chemical transporters, biochemical mediators, hormones, etc.
The blob operon produces enzymes that convert compound A into compound B. The operon is controlled by regulatory gene S. Normally, the enzymes encoded by the operon are synthesized only in the absence of compound B. If gene S is mutated, the enzymes are synthesized in the both the presence AND absence of compound B. Gene S must encode a(n):
a. inducer.
"Skin color is a classic variable trait in humans, and it's thought to be adaptive," Tishkoff said. "Analysis of the genetic basis of variation in skin color sheds light on how adaptive traits evolve, including those that play a role in disease risk."