This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
In the mitogen activated protwin kinase pathway , the activation of RAS is counteracted by 
Select and explain. 
A. Protein kinase C, B. GTPase activating protein, C. Phosphtidyl inositol, D. Inositol triphosphate
B: GTPase activating protein
Answer: B: GTPase activating protein 
Explanation: Ref Robbins 9/e p286 Activated rasvis present in association with GTP. Enzyme GTPase will degrade GTP to GDO and results in inactivation of RAS. Thus ,GTPase activating protein will counteract the activation of ras