Gene targeting

Gene targeting is a way of changing an organism's genes to make it different from the way it was before. It's like taking out pieces of the organism's genetic "recipe" and putting new pieces in instead. For example, scientists might target a gene that determines the color of a plant's leaves and change it so the plant has yellow leaves instead of green. The new gene would be like a new page in the recipe book, telling the plant to make yellow leaves instead of green.