How many strands of nucleotides make up RNA and DNA and what are they called?

it's actually thymine that is not present in rna... guanine pairs with cytosine by 3 hydrogen bonds and adenine pairs with uracil by 2 hydrogen bonds. There are two strands of nucloetides in DNA, the main strand being called the template or coding strand and will have the same base sequence as the mRNA synthesised during transcription (with thymine being changed to uracil). The other DNA strand is called the complimentary strand as it's bases compliment (match up with) the bases present on the coding strand. The coding strand dictates the order of the bases on the complimentary strand.