I have a few questions on DNA/RNA degredation and the mechanisms behind them.

General Discussion
1

These statements were taken from a journal article and I would like to learn why they are so, from the chemistry perspective.

Heres the article for those who requested for it: Lindahl, T. (1993). Instability and decay of the primary structure of DNA. nature, 362(6422), 709.

Why are base-sugar bonds of ribonucleosides much less susceptible to hydrolysis than those of deoxyribonucleosides?
Why is the de-purination rate of guanine faster than that of adenine, and both are faster than that of pyrimidines.
“The chemical price paid for the greatly increased resistance of the nucleic acid phosphodiester bond, gained by the removal of 2’ hydroxyl group, is a labile N-glycosyl bond.” Why is this so?
“Cytosine and 5-methylcytosine are main targets for hydrolytic de-amination. 5-methylcytosine moieties are de-aminated 5 times more rapidly than cytosines.” Why?

2
Why are base-sugar bonds of ribonucleosides much less susceptible to hydrolysis than those of deoxyribonucleosides?
from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349208/
The nature of the heterocycle in nucleoside deglycosylation reactions may be considered secondary to the role of the sugar moiety. It is, however, the specific identity of the heterocycle that dictates the relative stabilities of N-glycosyl bonds within a nucleoside class and this seemingly small detail may have been significant in the natural selection of the nucleobase repertoire. We have shown that even rather simple heterocyclic deviations from the native bases can significantly impact the reaction kinetics of N-glycosyl rupture. The native purine nucleosides and expectantly the native pyrimidine nucleosides do appear to exhibit the slowest deglycosylation kinetics under these conditions. We have also demonstrated that heterocycles have a unique contribution in the observed variation of rate enhancements when comparing deglycosylation kinetics of ribo→deoxyribonucleosides.
 
3

In the proper hands google is wonderful tool.

4

What a coincidence, I was going to say the same thing as the NCBI website. But I would have used big words and explained it in some boring, clinical way, so it’s probably best if I let their explanation stand.

CC, I agree. The google is a force for both good and evil, and in the hands of Tim, it’s pure goodness.