Slide subjects are microscopic organisms that can be studied under a microscope. The three most common slide subjects are Paramecia (9 letters), Amoebas (7 letters), and Amebae (6 letters). Paramecia are single-celled protozoans that live in aquatic environments and are characterized by their cilia, which they use to move and feed. Amoebas are also single-celled protozoans that move by extending pseudopods, or false feet. Amebae are similar to amoebas but are usually found in soil and freshwater. All three of these organisms are commonly studied in biology classes as they provide insight into the structure and behavior of living things.