All living things — including the fruits, vegetables and meat that we eat — contain genes that provide the instructions that tell the cells how to function. That information and many important traits are passed from generation to generation through genes, which are made of a large molecule called DNA, shaped much like a spiral staircase or “double helix.” Every living thing contains DNA. Scientists do genetic engineering by cutting and moving snippets of DNA from one plant, animal or microbe to another in a process called gene splicing. Genetic engineering can also include changing the expressing of a gene in a plant. Unlike traditional breeding techniques that simultaneously introduce many genes (including unwanted genes), genetic engineering is considered more precise since it introduces just the gene for a specific desirable trait.