Nucleosomes are
Identify $X$ and $Y$
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.
$DNA$ strand is directly involved in the synthesis of all the following except
Assertion : $DNA$ is associated with proteins.
Reason : $DNA$ binds around histone proteins that form a pool and the entire structure is called a nucleosome.