Answer:
organ system it belongs to the sensory system.
the level of organization go from
•cells
•tissues
•organs
•organ systems
•organisms
•population
•community
•ecosystem
•biome
•biosphere
Just say we have a big 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 helps :)
