This two page quiz assesses student understanding of interactions in ecosystems. First, students are asked to identify biotic and abiotic factors in an illustration of a pond ecosystem. Then, students must find and explain the following ecological relationships: competition, predation, and mutualism. They must then predict how the disappearance of one organism would affect the other populations in the community. Finally, they are asked to draw a food web for the illustrated ecosystem, and identify the herbivores, omnivores, and carnivores in the picture.