| A | B |
| hierarchical | persons or things ranked one above the other |
| feedback | a reaction or response to a particular process or activity |
| homeostasis | ability to main stability in response to a stimulus |
| biodiversity | variety among and within plant and animal species in an environment |
| cellulose | an inert carbohydrate in plant cell walls |
| organic | a substance derived from living material |
| mutualistic | a relationship among two organisms in which they both benefit |
| trophic level | relating to nutrition |
| keystone species | a species that has a disproportionate affect on other species in the environment |
| niche | function of an organisms in a community of plants and animals |
| quantitative | a numerical (number) value |
| justify | to show an act, claim or statement to be right |