He observed that many traits, from height to flower color, seemed to be controlled by these factors. Yet it wasn't until two researchers, Francis Crick and James Watson, proposed a double-helix structure for the molecule that we began to understand how this material carries the genetic code of life. A gene is a unit of information that can be passed on to offspring. Genes help determine whether your hair is straight, whether your eyes are brown, and whether you can curl your tongue. They also may help determine whether you'll get a certain disease, have a learning disability, or be a gymnastics champion.
Genes are powerful influences on physical and mental characteristics.
Yet genes don't exist only in people. Genes make hens white or speckled, give frogs smooth skin, and let roses smell sweet. Genes are found in all living things. As mighty as genes are, however, it's important to remember that environment also helps shape organisms. A person might have a genetic predisposition to be tall, yet be short because of poor childhood diet.