Although this may seem like an easy answer, a plant may be defined differently depending on group the people. An elementary school teacher may describe a plant as a “living green thing”, a high school teacher may narrow this definition, and a plant scientist may have a technical understanding of a plant. All these definitions serve a purpose and the definition needs to be modified depending on the audience. Plants are “green things”, which means they carry out a process called photosynthesis. There are many green, photosynthetic organisms, but some of these, such as bacteria, are not plants. Algae are a group of organisms that may be considered plants by some teachers, but would be called protists by scientists. This distinction is probably not important to school children; the important message is that these organisms use the sun to make their own food. In contrast, a group such as fungi, although plant-like, do not make their own food and should not be considered plants. For the purposes of this handout, we will concentrate on plants that live on land and are familiar to students of all ages and levels.