The primary research question of this thesis is bioluminescence of living beings and the extent to which it is represented and explained in a selection of middle school textbooks. The theoretical part of the thesis establishes general facts about bioluminescence itself, methods for teaching and gradual study of this topic in the distant past, as well as the importance of bioluminescence and its potential for use in today's world. In addition, this part includes a summary of the various means and motives of bioluminescence in select (model) groups of organisms (bacteria, fungi, algae, invertebrate, vertebrate). The didactically oriented part of the thesis involves an analysis of select textbooks that are frequently used Czech middle and gram...