Every plant, animal and person has genes. They are passed on from generation to generation. They make sure that humans give birth to humans or cows give birth to cows. They also make sure that a pig cannot give birth to a frog, or a horse to a dog. The recipe for a human being is contained in the 80,000 genes we inherit from our parents. These genes have the instructions that not only make us human but also determine things like skin colour and the shape of our nose. Scientists have known about genes for a long time. What they haven't known until recently is how to change them. Now they do. Genetic engineers put duck genes into chicken to make the chickens bigger. They put genes from flowers into soya beans and from scorpions into corn. British scientists managed to create the first "geep," an animal which is 50% sheep and 50% goat. Now people are wondering if the world will soon see another incredible sight: a clone of a human being. (from Speak Out, abridged)  Nanotechnology is the trendiest area of modern science. It is a form of molecular technology, which can combine biotechnology with atomic electronics. Put simply it is the technology of building very, very small things. Making thing? as small as a nonometre — one thousand millionth of a metre — might sound impossible, but today's scientists are building tiny machines and structures from components as small as single atoms. But why would anyone want to go to the trouble of moving single atoms around with highly sophisticated machinery? "Nanotechnology makes it possible to take all the atoms in your body and reassemble them. If you'rejust about to die of some nasty disease, we could send nanotechnology robots into your body and undo that damage and repair all of the cells," says a British scientist. "Nanotechnology can also undo your age. It can make a 90-year old man a young man of twenty-one again." The possibilities of nanotechnology are enormous. Nanotechnology is a fairly new area of research, and most of the work going on is to develop tools and techniques rather than practical inventions. But just as the space race gave us spin-offs like digital watches and ever-smaller computers, so nanotechnologists are already finding that their skills have a surprising range of uses.