What is the main role of decomposers in an ecosystem?

To break down dead and waste materials

The correct answer is Option (3) - To break down dead and waste materials

Decomposers, such as fungi and bacteria, play a crucial role in ecosystems by breaking down dead organic matter and waste materials. This process involves secreting digestive enzymes that decompose complex organic substances into simpler inorganic compounds. These simpler compounds are then absorbed by the decomposers and recycled back into the ecosystem. This decomposition process is essential for nutrient cycling, as it ensures that nutrients are made available to primary producers (such as plants) for use in their growth and development.

By decomposing dead matter and waste, decomposers help to clean up the environment and prevent the accumulation of dead material, thus maintaining ecosystem health and stability. Without decomposers, ecosystems would be overwhelmed with dead matter, and the nutrients locked in these materials would not be available for use by other organisms.