DNA is a tiny, threadlike substance inside every single one of your cells.
DNA is like a recipe for your body. It holds the code that determines everything about your physical being (eye color, height, body shape, hair color, ects).
DNA is made up of Genes that we receive from our parents. We receive half of our genes from our mother and the other half from our father. When the two genes about eye color match up in our DNA, the dominant gene will win over the the recessive gene. If you receive a brown eyes gene from your mom and a green eyes gene from your dad. Your eyes will be brown in color because brown eye color is a dominant gene.