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Decomposers | Useful Decomposers

Students explore how they use aerobic and anaerobic decomposers in their daily lives. They use anaerobic fermenters to make yogurt from milk.

Guiding Questions

How are aerobic and anaerobic decomposition similar and different?

How do we use each type of decomposers in our daily lives?

Activity – Useful Decomposers Worksheet


  1. Compare and contrast aerobic (cellular respiration) and anaerobic decomposition.
  2. Identify useful products of both kinds of decomposition.

NGSS Performance Expectations – see unit

Background Information

The goal of this lesson is for students to connect what they learned in the Decomposers Unit to products in their daily lives. Both aerobic decomposers that undergo cellular respiration and anaerobic decomposers working without oxygen break down large organic molecules. In the presence of oxygen (aerobic conditions), aerobic decomposers perform cellular respiration, producing CO2 and leaving very little substance behind. This process yields a lot of useful energy. Anaerobic decomposers often undergo fermentation. This process yields little in the way of useful energy and produces organic molecules that still have high-energy bonds that can be used as a food source for other organisms.

Key carbon-transforming processes: cellular respiration and fermentation

Talk and Writing

At this stage in the unit, the students will be applying unit ideas that should be well-developed. This is an opportunity to practice those ideas an additional time. The table below shows specific talk and writing goals for this phase of the unit.

Talk and Writing Goals for the Application Phase

Teacher Talk Strategies That Support This Goal

Curriculum Components That Support This Goal

Treat this as an opportunity to practice unit ideas

We’ve learned a lot about decomposition/cellular respiration in this unit. Let’s see how these ideas apply to our homes.

Listen for student ideas about matter and energy at different scales. Are they using unit ideas or informal reasoning?

What atoms from the decomposers’ food end up in the air? Can the remaining molecules be used by the larger organism?

Three Questions Poster from the unit

Help students practice using precise
language to describe matter and energy at different scales.

What is decomposition? What process is involved? How do atoms move during that process?

Molecule Poster

Three Questions Poster