Textbooks are one of the most important teaching aids in education. They often serve as the main or the only source of information for students and teachers. The aim of this study was to analyze the sources of students' scientific knowledge--teachers and textbooks, with focus on information about amphibians and reptiles. Authors have conducted an analysis of the content of twelve nature and biology textbooks, with the focus on: a core biological idea, the presence of surveys and summaries, appealing graphics and factual errors. The teachers participated in in--depth interviews, and were analyzed for the reflective insight considering e.g. presence of substantial mistakes or shaping students' attitudes. Authors proposed new framework for describing teaching styles based on the dominant characteristics of their teaching process, the teachers were classified as--Didactical, Pedagogical or Ethical teacher. None of the analyzed books were flawless. The most common errors concerned the movement apparatus and the taxonomy. Authors have found out statistically significant correlation between teachers with wider knowledge, and their declaration of more diverse and suitable methods during the lessons. Teachers who do not declare such activities were more probable to put less focus on shaping students attitudes and to make more errors.