At the University of Zagreb the Biology started developing as botany and zoology, since at that time those were the only biological disciplines. At what was then called the “Mudroslovni” faculty, professor Bohuslav Jiruš started botany classes on April 21^st 1876, and a bit later professor Spiridion Brusina started zoology classes. Biology, as did the other natural sciences, then developed within the Faculty of Philosophy until 1946 when the Faculty of Science (PMF) was established within which the Department of Biology and its two divisions of Botany and Zoology are included. The Division of the Physiology of Animals was established in 1963 (today it is called the Division of Animal Physiology), and the Division of Molecular Biology was established in 1989 and the Division of Microbiology was established in 2010. Today the Department of Biology is comprised of:

• Division of Botany
• Division of Zoology
• Division of Animal Physiology
• Division of Molecular Biology
• Division of Microbiology
• Botanical Garden

Other parts of the Department of Biology are:

• Division of Methodology for Teachers of Biology
• Division of Physical Education of the Faculty of Science  
• Central Biological Library