| Grade | Discipline | Core Idea |
|---|---|---|
| 3-5 | LS2.A: Interdependent relationships in ecosystems |
The food of almost any animal can be traced back to plants. Organisms are related in food webs in which some animals eat plants for food and other animals eat the animals that eat plants, while decomposers restore some materials back to the soil. |
| 6-8 | LS2.A: Interdependent relationships in ecosystems |
Organisms and populations are dependent on their environmental interactions both with other living things and with nonliving factors, any of which can limit their growth. Competitive, predatory, and mutually beneficial interactions vary across ecosystems but the patterns are shared. |
| 9-12 | LS2.A: Interdependent relationships in ecosystems |
Ecosystems have carrying capacities resulting from biotic and abiotic factors. The fundamental tension between resource availability and organism populations affects the abundance of species in any given ecosystem. |