♻️ap environmental science review

Microorganisms

Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 examWritten by the Fiveable Content Team • Last updated September 2025

Definition

Microorganisms are tiny living organisms that can only be seen under a microscope. They play a crucial role in various ecological processes, such as decomposition, nutrient cycling, and even human digestion.