Prokaryotes are completely indispensable to which chemical cycle?

• A. Carbon
• B. Phosphorus
• C. Water
• D. Sulfur
• E. Nitrogen

Answer: (E)

Verified step by step guidance

1. Understand the role of prokaryotes in chemical cycles: Prokaryotes, such as bacteria, play crucial roles in various biogeochemical cycles by facilitating the transformation of elements through different chemical forms.
2. Identify the nitrogen cycle: The nitrogen cycle is a biogeochemical cycle that involves the conversion of nitrogen into multiple chemical forms as it circulates among the atmosphere, terrestrial, and marine ecosystems.
3. Recognize the specific role of prokaryotes in the nitrogen cycle: Prokaryotes are essential in the nitrogen cycle because they perform nitrogen fixation, nitrification, and denitrification, which are key processes that convert nitrogen into forms usable by plants and other organisms.
4. Differentiate from other cycles: While prokaryotes are involved in other cycles like carbon and sulfur, their role in the nitrogen cycle is unique and indispensable because they are the only organisms capable of fixing atmospheric nitrogen into a biologically usable form.
5. Conclude the indispensability: Conclude that prokaryotes are completely indispensable to the nitrogen cycle due to their unique ability to convert atmospheric nitrogen into ammonia, which is a critical step that no other organisms can perform.