This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Metabolites of tryptophan can give rise to 
Select and explain. 
A. Diarrhoea, B. Vasoconstriction, C. Flushing, D. All of these
D: All of these
Answer: D: All of these 
Explanation: Serotonin (a metabolite of tryptophan) causes vasoconstriction, flushing, chronic diarrhea and respiratory distress due to bronchospasm.
Albinism is a defect in the metabolism of tyrosine due to deficiency of tyrosinase.