observe and describe the physical characteristics of environments and how they support populations and communities of plants and animals within an ecosystem;
Standard:
3.9.B
Description:
identify and describe the flow of energy in a food chain and predict how changes in a food chain affect the ecosystem such as removal of frogs from a pond or bees from a field; and
Standard:
3.9.C
Description:
describe environmental changes such as floods and droughts where some organisms thrive and others perish or move to new locations.
