DNA (Deoxyribonucleic acid)

Hello. I have a secret to tell you. I live deep inside you, and inside every plant and animal, too. I am like a tiny, secret recipe book. I hold all the instructions that make you, YOU. I help decide if you have curly hair or straight hair. I help choose if you have blue eyes or brown eyes. I am the special blueprint that tells your body how to grow big and strong and wonderful.

For a very, very long time, nobody knew I was there. I was a big secret. Then, way back in the year 1869, a scientist named Friedrich Miescher first found the stuff I am made of. But he didn't know my shape. It wasn't until the year 1953 that some very smart scientists figured it out. A brilliant woman named Rosalind Franklin took a special picture of me. It was like saying "cheese.". Using her picture, two friends named James Watson and Francis Crick built a model of me. They discovered I look like a twisty, twisty ladder. They called my shape a "double helix.". Isn't that a fun word to say. Double helix.

Now you know my secret shape. My name is DNA. Because scientists know what I look like, they can learn so many things. Doctors can learn how to keep you healthy and strong. Scientists can even learn about big dinosaurs from the DNA they left behind long ago. I am the special instruction book for every living thing, from a tiny bug to a big blue whale. I am so proud that I help make you one-of-a-kind and absolutely amazing.