This study aims to analyze the process under which biology lessons are taught in terms of teaching quality criteria (TQC). Teaching quality is defined as the properties of efficient teaching and is considered to be the criteria used to measure teaching quality both in general and specific to a field. The data were collected through classroom observations in this study, whose research was collected using a qualitative method. The research contained 21 classroom observations from 5 different biology teachers in 5 different high schools in Ankara, Turkey. The classes involved differing topics taught in 9th, 10th, 11th, and 12th grades. The data first underwent the structured content analysis using the MAXqda program. The encoding numbers for the codes in the data were transferred into the MS Excel program and were used to make quantitative analyses. The classrooms observed were grouped in terms of teaching quality criteria using cluster analysis using the SPSS 19 program. Similar groups, on the other hand, were evaluated according to cognitive structuring and teaching quality. As a result, avoiding the use of various methods, using effective teaching materials, and employing strict classroom management in biology teaching with the study group heavily increased the number of concepts communicated whereas problems in classroom management and classroom atmosphere reduced the concepts, thus influencing cognitive structure in a negative way. Finally, asking deepening questions and evaluative feedback affected cognitive structure in a positive way.