Nucleic acids were discovered by

Histones are rich in the basic amino acid ...............and........

In the $340 A^o$ long $DNA$ strand

..............is common for both $DNA$ and $RNA$ but.............is present only in $DNA$

Assertion : In a $DNA$ molecule, $A-T$ rich parts melt before $G-C$ rich parts.

Reason : In between $A$ and $T$ there are three $H-$ bond, whereas in between $G$ and $C$ there are two $H-$ bonds.

Retroviruses do not follow central Dogma. Comment