In the dna double helix archaic pairs with thymine and cytosine pairs with guanine

False

Adenine which is a purine base, always pairs with the pyrimidine Thymine in DNA and Uracil (also a pyrimidine) in RNA. The bond which is present between the two bases is a double hydrogen bond.

Guanine which is also a purine base, always pairs with the pyrimidine Cytosine, in the case of both, DNA and RNA. The bond which is present between the two bases is a triple hydrogen bond and hence, is stronger than the A-G double bond.