I believe it’s an active dye?
The dominant and recessive pair, A
There are lots:
Biology and Medicine - cloning and expression of human insulin in bacteria (stopped having to produce it from pig pancreases); Watson & Crick discovery of the structure of DNA; gene therapy in humans
Chemistry - determination of the exact number of molecules in a mole (Avagadro's number); discovery of radioactivity (Rutherford); the invention of nylon (DuPont); Boyle's law (behavior of gases)
The cycle that is described in the problem is called the water cycle. in this cycle, the water from a lake is evaporated through the heat of the sun and the water is accumulated in the clouds. When the clouds are saturated, then water condenses and precipitates to fall as rain.