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: Social & Preventive Medicine
Conditionally Essential amino acids are 
Select and explain. 
A. Tyrosine & Cysteine, B. Histidine & Arginine, C. Leucine & Lysine, D. Phenylalanine & Tryptophan
A: Tyrosine & Cysteine
Answer: A: Tyrosine & Cysteine 
Explanation: Conditionally Essential Amino Acids (CEAA):
Non-essential amino acids may turn essential if their precursors are limited in the body
– There are 2 CEAA, namely, Tyrosine (derived from Phenyalanine) and Cyteine (derived from methionine)