How closely matching sets of genes can belong to entirely different species is one of the great mysteries of modern biology. However, not all differences between species can be explained by gene differences alone. At present we do not fully understand the nature of these specific features, and. These features determine whether a sequence is a gene or not, and so by definition are not possessed by non-coding DNA. Because of this close similarity, scientists think that it is the sequence of genes, as well as the types of genes themselves, that account for most of the differences between the two species. Sequence inspection can be used to locate genes because genes are not random series of nucleotides but instead have distinctive features. Just how different are the genes making up different life forms? In the case of the human and the chimp, not much: about 98 percent of the DNA in a chimpanzee cell is identical to the DNA in a human cell. The kinds of proteins, the amounts, and the order in which they are made all help determine how one type of cell differs from another and, ultimately, how one species of organism differs from another. These proteins are used to repair cells and make new ones.

Genes contain the chemical information needed to create different kinds of proteins. Each gene is a specific segment of DNA, occupying a fixed place on a chromosome. Did You Know? What makes a human different from a chimpanzee? Much of the answer lies in the genes, the basic units of heredity.

Bushes gene sequence definition