In what way do $DNA$ and $RNA$ differ?

What is required for the packaging of chromatin at a higher level?

The proposal of the double helix structure of $DNA$ was based on the observations of which of the following scientists?

Which type of $RNA$ is found in the highest quantity in a cell?

In a segment of eukaryotic $DNA$,if the purine bases are $40$,then what will be the number of pyrimidine bases?

$A$ $DNA$ fragment contains $120$ adenine and $120$ cytosine bases. What is the total number of nucleotides present in this fragment?