If genes are responsible for determining some of our behaviour, that is the way the world is - it is neither good nor bad. Knowledge can be used for both good and evil. Of course, scientists in their work have the responsibilities of all citizens to do no harm and be honest. Their additional responsiblity is to put their work and its possible applications in the public domain. Rotblat does not want to distinguish between scientific knowledge and its application, but the very nature of science is that it is not possible to predict what will be discovered or how these discoveries could be applied.
Cloning provides a nice example.
The original studies related to cloning were largely the work of biologists in the 1960s. They were studying how frog embryos develop and wanted to find out if genes which are located in the cell nucleus were lost or permanently turned off as the embryo developed. This involved putting the nuclei of cells from later stages in development, including adult cells, back into an egg from which the nucleus had been removed to determine whether the genes in that nucleus would allow the egg to develop. Nuclei from some adult cells could allow the egg to develop and this showed that the genes were still capable of being expressed in the correct way. It was incidental to the experiment that the frog that developed was a clone of the animal from which the nucleus was obtained.