Detritivores ingest detritus for energy; which group chemically breaks down organic matter, returning nutrients to the environment?

• A. Detritivores
• B. Herbivores
• C. Predators
• D. Decomposers

Answer: (D)

The main idea here is nutrient cycling driven by decomposers. Decomposers chemically break down organic matter using enzymes, turning complex molecules into simpler inorganic nutrients like carbon dioxide, water, and mineral nutrients that plants can reuse. This mineralization process frees up elements such as nitrogen and phosphorus, keeping ecosystems fueled for growth.

Detritivores, on the other hand, mainly ingest detritus and physically fragment it into smaller pieces. That increases surface area and helps with decomposition, but the core chemical breakdown and nutrient release come from decomposers, especially fungi and bacteria thriving in soil and on decaying matter.

So, the group that chemically breaks down organic matter and returns nutrients to the environment is decomposers.