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
The sequence that targets protein to lysosmoes 
Select and explain. 
A. Glucose 6 - phosphate, B. Mannose 6 - phosphate, C. Ribose 5 - Phosphate, D. Fructose 1 - phosphate
B: Mannose 6 - phosphate
Answer: B: Mannose 6 - phosphate 
Explanation: Mannose 6 - phosphate acts as a tag for the proteins to reach lysosomes. Defects in the process of tagging  this sequence to protein result in I - Cell disease.