Here we're told that a pentanucleotide has a base sequence of g a u c a. Based on the given sequence, what is its likely origin? So where does this sequence originate from? And we can figure this out based on this sequence. So these are our nitrogenous bases. Because they're nitrogenous bases, that will rule out fructose which is a carbohydrate, and oleic acid because it's a fatty acid. Because these are nitrogenous bases, that means that it's going to be either DNA or RNA. Now, what are the key differences between them?
Remember, the key difference is that DNA uses thymine as one of its nitrogenous bases, abbreviated T, and RNA uses uracil, abbreviated U. Since there is a uracil involved within this sequence, it would have to be RNA that's being discussed here. So here, our final answer would be option C. This represents RNA as the origin for this nucleotide or base sequence.
