Describe in short about $RNA.$
 

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 etc. evolved around $RNA.$

$RNA$ used to act as a genetic material as well as a catalyst.

But $RNA$ being a catalyst was reactive and hence unstable.

Therefore $DNA$ has evolved from $RNA$ with chemical modifications that make it more stable.

$DNA$ being double stranded and having complementary strand further resists changes by evolving a process of repair.

The nitrogenous base 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.