Treatment of DNA and RNA with alkali causes RNA hydrolysis but DNA is protected. Why?

DNA cannot be hydrolyzed by alkali because its pentose sugar does not contain the 2′-OH that is responsible for base-catalyzed hydrolysis mechanism, while RNA has 2-OH on its sugar which aids in this hydrolysis.
Explanation:
There are several differences between RNA and DNA in their structure. One of the differences is that RNA pentose sugar is oxidized on the second carbon atom, while DNA pentose sugar is deoxygenated on the second carbon atom. The hydrolysis is through a nucleophilic attack of 2’OH, converting it to nucleophile which causes intramolecular displacement and eventual cleavage of phosphodiester bond. DNA lacks this 2′-OH hence stable under alkali conditions