Unit Checkpoint: Ecosystems & Energy Flow

Producers are organisms like plants and algae that make their own food through photosynthesis, using energy from sunlight. They form the base of all food webs.

The 10% rule states that only about 10% of energy transfers from one trophic level to the next. So if a plant has 1000 calories, only about 100 calories (10%) will be available to the rabbit.

Energy pyramids get smaller because organisms use most of their energy for life processes (movement, growth, reproduction) and much is lost as heat. Only about 10% is passed to the next level.

A food web shows ALL the feeding relationships in an ecosystem - many interconnected food chains. Most organisms eat more than one type of food, so food webs are more realistic.

With fewer predators (foxes), more rabbits would survive. This would cause the rabbit population to increase, at least initially.

Mushrooms are decomposers. They break down dead organisms and return nutrients to the soil. Hawks are consumers, rabbits are herbivores, and grass is a producer.

CER stands for Claim, Evidence, and Reasoning. Evidence is the data or observations that support your claim.

Secondary consumers eat primary consumers (herbivores). For example, a snake that eats a mouse is a secondary consumer.

Because only 10% of energy transfers between trophic levels, there isn't enough energy at the top of the food web to support large populations of predators.

Decomposers break down dead plants and animals, releasing nutrients back into the soil. These nutrients are then absorbed by plants (producers) to grow, continuing the cycle.