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
Which of these is a conservative mutator 
Select and explain. 
A. Glutamic acid-glutamine, B. Histidine-glycine, C. Alanine-leucine, D. Arginine-aspartic acid
C: Alanine-leucine
Answer: C: Alanine-leucine 
Explanation: Conserved mutation means altered AA has same properties of original AA. e.g. glutamic acid to aspartic acid (both acidic) or alanine to leucine (both aliphatic).