We all have 99.9% of similar genetic material in each of us and that's why that we are all humans. Now a question will appear in your mind that "I'm not looking like a Chinese or an American, so how do we have 99.9% similar DNA?" It's answer is that, it is only 0.1% of DNA that makes a difference between you and other person. Their appearance will be different from you, only due to this small fragment of DNA. In other words, we all have 3 billion base pairs present in our DNA. These base pairs are the main stores of our genetic information. Out of these 3 billion base pairs, only 3 millions or 30 lakhs base pairs made us to look different from each other. These 3 million base pairs also influence our health conditions or immunity conditions.