If a DNA sample were composed of 10% thymine, what would be the percentage of guanine? 15:09 Biology Chapter 5 If a DNA sample were composed of 10% thymine, what would be the percentage of guanine? A) 10 B) 20 C) 40 D) 80 E) impossible to tell from the information given Answer: C) 40 Learn More : Share this Share on FacebookTweet on TwitterPlus on Google+