How many polynucleotide chains are present in the structure of $DNA$?

Thirty percent of the bases in a sample of $DNA$ extracted from eukaryotic cells is adenine. What percentage of cytosine is present in this $DNA$ (in $\%$)?

$DNA$ differs from $RNA$ in:

Nucleotides are linked by

The unit of inheritance is.

The telomeres of eukaryotic chromosomes consist of short sequences rich in: