Indiana Grade 5 Science

Trace matter through an ecosystem without making energy cycle

Build an original garden-ecosystem model connecting plants, animals, decomposers, air, water, and soil, then explain each matter arrow.

The Indiana science standards directory links grade-specific documents for the 2023 Indiana Academic Standards. Use the 2023 Indiana Academic Standards: Grade 5 Science for the selected performance expectation and its complete supporting information. This activity selects a Grade 5 expectation. It is one part of a science course, not a complete curriculum.

Where does the material in a bean plant go next?

A class builds a simplified model of a garden ecosystem with bean plants, a rabbit, fungi and bacteria, and the surrounding air, water, and soil. The model follows matter entering plants, moving when an animal eats plant material, and returning to the environment through several processes. It is an original teaching model, not a claim that one bean plant is a complete ecosystem or that all interactions in a real garden have been recorded.

Explain the evidence or model

Plants take in carbon dioxide from air and water and use light energy to make food. They also take in mineral nutrients; soil minerals are not the plant’s main source of the material used to build its body. When a rabbit eats plant material, some matter moves into the animal. Dead plant parts and animal remains can be broken down by decomposers, and some materials return to the soil. Matter also moves between organisms and air or water, so an adequate model needs more than a single plant-to-rabbit arrow. Each arrow should name the material or process represented. Light supplies energy for food production; do not label sunlight as matter eaten by the plant.

What to check in the explanation

A food arrow and an energy arrow can be drawn on the same model, but their labels must keep the ideas distinct. Matter can cycle among organisms and the environment; energy is transferred and ultimately dispersed as heat rather than endlessly recycled through the same loop. Decomposers are living organisms, not merely a pile of dead leaves. They use material from what they break down, and their role is not to manufacture all matter from nothing. This simplified model omits many organisms and pathways, so a student should describe those omissions instead of calling the drawing a complete garden food web.

Plan the next activity

1. Name the organisms and environmental parts inside the model’s boundary.
2. Draw and label matter pathways, including decomposers and the environment.
3. Explain a pathway and identify a missing connection or model limitation.

Start with the table, then draw an original model with separate labeled arrows for matter and for light energy. Explain how material could move from air into a plant, into an animal, and back to the environment. Add dead plant material reaching decomposers rather than requiring every pathway to pass through the rabbit. Ask a partner to follow the arrows and point out any unexplained jump. Revise the model in response. A teacher-selected source about a real local ecosystem can provide evidence for a later version with different organisms. The selected Indiana expectation is marked essential in the state document; that designation does not make this one model the whole Grade 5 life-science course.