Tryptophan self-controls its synthesis. If we have a large amount of tryptophan in the sense that it exceeds, tryptophan would act as a co-repressor which prevents synthesis of more enzymes for its production. Hope this answers the question.
Two possible answers, the plant kingdom or the eukaryotic kingdom because the plant is within this category along with animals.
Oxygen breakdown the food and release energy molecules as ATP
The answer is B. The reason is because in an RNA strand, A turns into U.
