Genes

Genes are like little instruction cards inside your body. They tell your cells how to make you. Genes decide the color of your eyes, hair, and skin. You get your genes from your parents. That is why kids often look like their moms and dads.

How Genes Work

Genes are made of DNA. DNA looks like a twisted ladder. Each gene is a small part of that ladder with its own job. Some genes tell your body to grow taller. Others decide if you have freckles or dimples. Every cell in your body has the same set of genes.

Passing Genes Down

You got half your genes from your mother and half from your father. That is why you might have your mom's eyes and your dad's smile. Brothers and sisters can look alike because they share many genes. Twins who are identical share all of their genes. Genes pass from parents to children for generations.

Fun Facts

• Humans have about 20,000 different genes.
• People share about 99 percent of their genes with each other.
• We share about 60 percent of our genes with a banana.

Did You Know?

Scientists finished mapping all the human genes in the year 2003. This big project took 13 years to complete.