Which of the Following Would Have the HIGHEST Melting Temperature

Question

Which of the following would have the HIGHEST melting temperature?
A) 20-mer double-stranded DNA-DNA duplex
B) 20-mer double-stranded RNA-RNA duplex
C) 40-mer double-stranded DNA-DNA duplex
D) 40-mer double-stranded DNA-RNA duplex
E) 40-mer double-stranded RNA-RNA duplex

Accepted Answer

The 40-mer double-stranded RNA-RNA duplex (E) would have the highest melting temperature due to the stronger hydrogen bonding and the presence of an additional hydroxyl group in RNA compared to DNA, which stabilizes the duplex structure. Longer strands and RNA-RNA duplexes generally have higher melting temperatures.