Which of the following statements best describes the ecological significance of prokaryotes?

• A. Prokaryotes are exclusively pathogenic and do not contribute to ecological processes.
• B. Prokaryotes are only found in extreme environments and have little impact on global ecosystems.
• C. Prokaryotes are unable to survive without a host organism.
• D. Prokaryotes play a crucial role in nutrient cycling, such as nitrogen fixation and decomposition.

Answer: (D)

Verified step by step guidance

1. Understand the role of prokaryotes in ecosystems by reviewing their metabolic diversity and ecological functions.
2. Recognize that prokaryotes include bacteria and archaea, which are found in virtually all environments, not just extreme ones.
3. Recall that many prokaryotes are involved in nutrient cycling processes, such as nitrogen fixation, which converts atmospheric nitrogen into forms usable by plants.
4. Consider the role of prokaryotes in decomposition, breaking down organic matter and recycling nutrients back into the environment.
5. Evaluate the given statements by comparing them to these ecological roles, identifying that the statement highlighting nutrient cycling and decomposition best describes the ecological significance of prokaryotes.