About 74 percent of people may have a type of giant DNA hiding in their mouth.
Why it is true
Researchers at the University of Tokyo discovered Inocles, extrachromosomal DNA elements with an average of 350 kilobase pairs, one of the largest ever found in the human microbiome. These structures help mouth bacteria adapt and may influence oral health.
Source: University of Tokyo
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.