Write a short note on the $RNA$ World.

(N/A) Ribonucleic Acid $(RNA)$ was the first genetic material to evolve.
It is evident through various scientific researches that essential life processes,such as metabolism,translation,and splicing,evolved around $RNA$.
$RNA$ acted as both a genetic material and a catalyst (ribozyme).
However,because $RNA$ acted as a catalyst,it was reactive and hence unstable.
$\Rightarrow$ Therefore,$DNA$ evolved from $RNA$ with chemical modifications that made it more stable.
$DNA$,being double-stranded and having a complementary strand,further resists changes by evolving a process of repair.
The nitrogenous bases in $RNA$ are of two types: $(i)$ Purines (Adenine and Guanine),$(ii)$ Pyrimidines (Cytosine and Uracil).
Ribose sugar $+$ Nitrogenous base $\rightarrow$ Ribonucleoside.
Ribonucleoside $+$ Phosphate group $\rightarrow$ Ribonucleotide.