Alright. So here we have an example problem that wants us to complete the blank here using one of these 6 potential answer options down below. And the example problem says the purine nitrogenous bases are blank. And so, of course, if we recall from our last lesson video that one of the ways we can use to help us remember the purine nitrogenous bases is to remember purines are pure as gold. And so by remembering pure as gold, we can see that the 'a' in the 'as' is for adenine and the 'g' in the 'gold' is for guanine.
And so adenine and guanine are the purines. And so, of course, when we look at the answer options, we can see that option e says adenine and guanine. And so that is going to be the correct answer for this example problem and all of the other ones are incorrect. And so that concludes this example problem and I'll see you all in our next video.