Answer:
The correct answer is "the induced fit model".
Explanation:
The first model that looked to explain the enzyme and substrate interaction was the "lock and key" model. Although this model helped scientists to understand the specificity nature of the interaction enzyme-substrate, it does not reflect reality since enzyme was portrayed as a lock with a structure that doesn't change during the catalysis. Then half century later "The induced-fit theory" was proposed which fits much better the newer version of the enzyme action model. In this theory the enzyme is partially flexible and its structure changes as a result of its interaction with the substrate.
TAC AAC GAC are the complementary nucleus acid bases
The expressed (coding) regions of eukaryotic genes are called EXONS.
Well there is not much to go off of, but I am very confident the answer would be studying fossil records,
