Why is using reverse transcriptase necessary for finding a way to make artificial insulin

This is a biological reaction due to a stimulus. i need this quickly !

Water changes bacteria in the soil converts this nutrient into a usable form. plants take up the usable nutrient through the soil and assimilate it into proteins, making it part of the plant. an animal eats the plants, and the nutrient becomes part of the animal. when the animal dies, it decomposes, returning the nutrient back to the soil. which cycle is being described? water cycle carbon cycle nitrogen cycle phosphorous cycle

How does this procedure serve as a method of birth control?