Imagine you have discovered a new species of bacteria. To begin your investigation of this organism, you run an assay on the total nucleotide content of the bacterial RNA. If the cytosine content of RNA from the bacterial cells is 40%, what is the adenine content?

The correct answer is 10%

Explanation:

According to the chargraff's rule, the ratio of purine and pyrimidine is equal to 1  which means purine is equal to pyrimidine. It also says that some of adenine and guanine is equal to the sum of cytosine and thymine. So adenine must be equal to thymine and guanine must be equal to cytosine.

So if cytosine amount is 40% then the amount of guanine would be also 40% so the remaining 20% would be made by adenine and uracil in RNA so adenine would make 10%. Therefore the correct answer is 10%.