What are the DNA-DNA complimentary base pairing rules?

1 Answer
Jul 27, 2016

Adenine pairs with thymine and guanine pairs with cytosine.

Explanation:

The DNA molecule is a double helix which consists of two strands of polynucleotides. If you know the sequence of nitrogenous bases on one strand, it is easy to determine the base on the opposite strand.
The maintain the correct width of the molecule, a purine ( adenine or guanine) must pair with a pyrimidine. Hydrogen bonding holds the two strands together. Adenine forms two hydrogen bonds with thymine and cytosine forms three hydrogen bonds with guanine. It is for this reason that adenine cannot bond with cytosine and guanine cannot bond with thymine.