The Human Genome Project has the goal of learning about the human genome, but researchers involved also are studying the genomes of a form of yeast, a fruit fly, a mouse, a plant, and many bacteria . Researchers are studying the genomes of these species to learn about the similar, but more complicated, genome of human beings. What they learn from the genes of one species is helping them understand how genes work in all species. Genetic engineering can produce crops that are more resistant to disease or that taste better. One way to learn is by taking the object apart.
Genetic researchers do the same thing.
They cut apart the genome to figure out what the individual parts do. Researchers have found ways to slice genes out of a genome. They have learned how to make changes to a gene and how to replace one gene with another. Say, for example, that researchers want to find out what different genes do in a particular kind of flowering plant. They can take a seed from that plant and use a special technique to get inside its genome.