The study of the traits you inherit from your parents is called genetics. Scientists all over the world have worked to understand human genetics as well as the genetics of other living things.

In the top left corner we see a cell. All living things are made up of one or more cells. You are made of trillions of cells all working together.

The nucleus is the part of the cell that contains DNA (deoxyribonucleic acid)

DNA tells your cell what to do. It is kind of a code for life.

Each nucleus in each cell in your body has 23 pairs of long pieces of DNA called chromosomes. You got half of each pair from your mother and half of each pair from your father. That’s 46 all together.

That’s 46 all together. Your chromosomes are made up of smaller pieces of DNA called genes.

Notice that DNA looks like a twisted ladder.The “sides” of the ladder are made of a sugar (deoxyribose) and a phosphte group.

DNA is also made up of four pairs of bases that are the code of your genes. These are called nucleic acids. The bases are thymine, adenine, cytosine and guanine. They make the “rungs” on the ladder.

When you are building your gene you must use the rules of the DNA code. Cytosine k-nex can only combine with Guanine k-nex. Adenine k-nex can only combine with Thymine k-nex. Those are the rules. It always works that way so that there are no mistakes in the code when DNA makes copies of itself. Follow the rules.