Biology is an interdisciplinary field of science which is constantly evolving with the progress of research. It is the science of living things: its fields (animals, plants, micro-organisms, viruses, etc.), its evolution and its interactions with the environment. A simplification of the various biological concepts while respecting a hierarchy and a very appropriate lexicon will certainly help the student to improve his knowledge in this science and will allow him to communicate well and give his opinion in the different themes of this science.