This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
Maize is deficient in which amino acid 
Select and explain. 
A. Leucine, B. Methionine, C. Tryptophan, D. Phenylalanine
C: Tryptophan
Answer: C: Tryptophan 
Explanation: The proteins of maize are deficient in tryptophan and lysine; while some strains contain an excess of leucine. Excess of leucine or deficiency of tryptophan causes decreased synthesis of niacin in the body. This explains the pellagragenic action of maize.