The aim of this thesis was to analyse the DABAR repositories of diploma theses done at the Department of Biology, Faculty of Science, University of Zagreb from 2006 to 2021 in order to: (i) assess the interest of students of biological orientation for individual biological areas and (ii) become aware of trends in biological science and education at the Department of Biology, Faculty of Science, University of Zagreb during the last 15 years (from 2006 to 2021). The obtained results were subjected to descriptive statistical methods, and additional statistical analyses were applied to test for significant differences in the number of graduate theses between individual years and individual fields of work. In the period from 2006 to 2021, most graduate theses were done within the Division of Zoology of the Department of Biology, Faculty of Science, University of Zagreb. Most graduate theses (45%) during the last 15 years (2006-2021) were made in the field of work related to plant or animal cell cultures and/or laboratory-grown organisms, and the lowest numbers of graduate theses (2%) were recorded in in the field of biology education. Over the years, a relatively uniform trend of growth and decline in the number of graduate theses between individual divisions of the Department of biology and research areas was observed. It also was proven that in 2006, significantly lower number of graduate theses was recorded compared to other years, probably because this is the first year included into the DABAR repository and it is possible that not all graduate theses from this year were entered in the DABAR database. Trends in the growth and decline of the number of graduate theses within individual departments of the Department of Biology / research areas are probably due to the dynamics of research trends, the popularity of certain biological topics and research activities (scientific projects) at individual divisions of the Department of biology in a given period.