What rule is used to join the free nucleotides to the exposed bases of the DNA?

1 Answer

The base-pairing rule describes how the nitrogen bases pair with one another.

Explanation:

For DNA replication, the base-pairing rule states that adenine always pairs with thymine, and cytosine always pairs with guanine.

For transcription from DNA to mRNA, the base-pairing rule states that adenine in DNA always pairs with uracil in mRNA, and cytosine always pairs with guanine.

DNA REPLICATION
http://www.ucl.ac.uk/~sjjgsca/DNApairing.html

TRANSCRIPTION FROM DNA TO mRNA

http://www.chemguide.co.uk/organicprops/aminoacids/dna3.html