A Powerpoint file of 40 picture cards that I created using my free template. You can edit the background color. There is a student activity sheet included with a detailed answer key. These cards are for the Ecology or Environmental Unit within Biology or General Science. They can be used for an Environmental course too. The students determine which pictures are biotic and which are abiotic and sort them. Then, they record their answers on the student sheets. There are some purposefully challenging ones for students, but an answer key with a detailed explanation is provided.