Deoxyribonucleic or DNA carries nucleotides or chemical bases that makes up each individuals genetics. DNA is carried by chromosomes. Humans inherit one set of 23 chromosomes from their mother and another set from their father. 22 of the sets are very similar but with a slightly different version of each gene on the chromosome. The pairing determines our sex. Females have two X chromosomes but males have one X chromosome and one Y chromosome. The Y chromosome carries the genes that create masculine features. DNA provides all the information needed for an organism to develop, survive and reproduce. There are pairs of chemical bases which form long sequences called genes. Genes are coded instructions for building proteins. Each gene produces one protein. These proteins are building blocks of the body. When isolated from the cell and stretched out the DNA looks like a twisted ladder which is called a double helix. The sides of the DNA are called the backbone and the steps are pairs of chemical bases that are arranged in a particular order. The four types of chemical bases are adenine, thymine, cytosine and guanine. In my model the backbone is made up of licorice and the chemical bases are made of marshmallows held by toothpicks. My marshmallows are arranged in a specific order to show how adenine (green) always pairs with thymine (pink) and cytosine (yellow) goes with guanine (orange).