The smallest structure having the power of replicating itself is:

Which structure contains the coded information required to produce the chemicals necessary for performing parental functions?

Which molecule contains all the information required for carrying out all life processes?

Which of the following is correct for calculating the total length of $DNA$?

In a $DNA$ molecule,.................

Assertion $(A) :$ The distance between two polynucleotide chains in $\text{dsDNA}$ remains constant.
Reason $(R) :$ Always a purine comes opposite to pyrimidine or vice versa.