Science: Ecosystems & Food Chains: Challenge

# Hard Level Guide Stretch thinking with multi-step problems, application questions, and deeper reasoning. # What Is an Ecosystem? An ecosystem includes all living things in an area plus the nonliving parts they interact with, such as water, soil, and sunlight. Forests, ponds, and deserts are different ecosystems. Organisms depend on each other and on their environment to survive. # Producers, Consumers, and Decomposers Producers make their own food through photosynthesis. Plants and algae are producers. Consumers eat other organisms for energy. Herbivores eat plants; carnivores eat animals. Decomposers break down dead matter and return nutrients to the soil. # Food Chains and Food Webs A food chain shows one path of energy from the sun to a top consumer. Arrows point in the direction energy flows. A food web shows many connected chains in an ecosystem. Removing one species can affect others in the web. # Balance and Change Ecosystems can be disrupted by drought, pollution, or loss of habitat. Conservation efforts protect biodiversity. Students should describe relationships using scientific vocabulary and explain what happens when a link in a chain is removed.