In the last years, there has been a quick increase in the development of genetic technologies with important economic, ethical or social implications which are provoking many questions of great relevance, such as: which will be the effects of the genetic therapies on human genetic heritage, who must have the control on the development and the use of new technologies, etc. Young students are part of a society in which these and other subjects related to genetic will be more and more common, and they will be demanded to make substantiated decisions. Nevertheless, generally we have little knowledge of the level of understanding that the young population has of the modern Genetics, as well as of their opinions and attitudes to the questions in this field.

The knowledge and understanding of the adolescents on scientific subjects in general, and on genetic in particular, as well as their opinions and attitudes, are due, on the one hand, to formal education and, on the other hand, to the informal education which is essentially acquired thanks to mass media.

Many investigations have shown that the learning of students on genetic subjects is less significant than it should be. Throughout the time there have been many investigators interested in analizing the causes that mainly make difficult the learning of the contents of Genetics for formal education: from the seventies to the present time the most difficult genetic contents to learn or to explain have been tried to determine; even possible didactic alternatives have been proposed. The knowledge of the conceptions of our students can help us to base suitable educational strategies that allow a significant learning, since the learning process is seen now not only like a conceptual change but also like ontological, epistemologic, methodologic and axiologic change.

But the conceptions that the students generate with respect to highly topical subjects such as genetics or molecular biology are essentially obtained from mass media, mainly from television; more and more programs or films use genetic subjects in their arguments and plots. From mass media our students receive this information directly and in many cases great mistakes are committed which could generate didactic obstacles.

In summary, the great social development that the Genetics is acquiring, their wide media coverage, the incorporation of this matter in the curriculum of secondary education, the difficulties found in the learning of genetic are some of the reasons that make necessary a deeper investigation through a didactic perspective of the process of education and learning of the genetics. Therefore in this work aspects related to the education of the genetics have been analyzed from both the point of view of the formal education and from the informal one (conceptions of the students, meaning transmitted by mass media, the official curriculum, etc) showing some possible difficulties in the acquisition of the significant knowledge on the part of the students.