The book is devoted to ethical problems arising when using modern achievements of molecular genetics and experimental embryology in medical practice. In a popular form accessible to a layman, the latest achievements of genetics are outlined. The possibilities of selecting genetically "desired" children at an early embryonic stage, changing the genome by genetic engineering, human cloning and the so-called therapeutic cloning are considered. The danger of the spread of pseudoscientific and immoral theories that allow society to interfere with inalienable human rights is shown.