Describe in short about $RNA$.

(N/A) Ribonucleic Acid $(RNA)$ was the first genetic material to be discovered.
It is evident through various scientific researches that essential life processes such as metabolism,translation,and splicing evolved around $RNA$.
$RNA$ used to act as a genetic material as well as a catalyst.
However,$RNA$ being a catalyst was reactive and hence unstable.
Therefore,$DNA$ evolved from $RNA$ with chemical modifications that make 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.