I think you wrote this wrong? Is it not round rr vs wrinkled RR?? I'll answer it with that assumption:
You are crossing a rr with an RR:
You only get Rr back so they will phenotypically be all wrinkled
If you are crossing rr with an Rr (so a heterozygote wrinkled):
50% will be Rr (wrinkled)
50% will be rr (round)
See my picture for the Punnett Squares for both answers!
A nucleotide consists of three things: A nitrogenous base, which can be either adenine, guanine, cytosine, or thymine (in the case of RNA, thymine is replaced by uracil). A five-carbon sugar, called deoxyribose because it is lacking an oxygen group on one of its carbons. One or more phosphate groups.
The answer is Deoxyribose