Activity #2. Encircle the letter of the best answer. 1. What is the area in which an organism lives? a. Ecology b. environment c. habitat d. niche 2. What is the role an organism plays within an ecosystem and the factors required to support that role? a. Ecology b. environment habitat d. niche 3. What is the relationship between two organisms in a community? a. Commensalism b. mutualism c. parasitism d. symbiosis