For any information you have borrowed or used that is not your own work (model, theory, picture, figure, or quotation etc.) you need to acknowledge your sources.

There are two ways to do this: either put the reference on the slide, or if that clutters your slides too much, in the bibliography on the last slide. For the latter, follow the APA-style (see the UU Library website). Also, remember to indicate when you use your own personal photographs.