Guanine pairs with cytosine in DNA. The base-pairing rules in DNA are strict, meaning that no nucleotide pairs with any other nucleotide except for its designated partner. The designated partners form complementary base pairs with each other as follows: adenine pairs with thymine, and guanine pairs with cytosine. The hydrogen bonds between the complementary base pairs hold the two strands of the DNA molecule together. The consistent pairing of bases allows DNA to accurately replicate itself and be transcribed accurately into RNA and then translated from RNA to amino acids.