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
Thermo-stability in DNA is contributed mostly by: 
Select and explain. 
A. A=T, B. GEC, C. Molecular base, D. Parallel arrangement
B: GEC
Answer: B: GEC 
Explanation: B i.e. G CThermostability in DNA is constributed mostly by C GQ because there are 3 Hydrogen bonds between C & GQ. G C bonds are much more resistant to denaturation or melting than A= T rich region (2 Hydrogen bonds)