Which of the following are roles that prokaryotes play in the cycling of elements in an ecosystem?

• A. Pollination and seed dispersal
• B. Nitrogen fixation and decomposition
• C. Photosynthesis and respiration
• D. Water filtration and soil erosion

Answer: (B)

Verified step by step guidance

1. Understand the role of prokaryotes in ecosystems: Prokaryotes, which include bacteria and archaea, are crucial in various biogeochemical cycles, helping to recycle nutrients essential for life.
2. Identify nitrogen fixation: Prokaryotes, particularly certain bacteria, convert atmospheric nitrogen (N₂) into ammonia (NH₃), a form that plants can use. This process is vital for incorporating nitrogen into the ecosystem.
3. Recognize decomposition: Prokaryotes decompose organic matter, breaking it down into simpler substances. This process releases nutrients back into the soil, making them available for other organisms.
4. Differentiate from other roles: Pollination and seed dispersal are primarily roles of animals and plants, not prokaryotes. Photosynthesis is mainly performed by plants, algae, and some bacteria, while respiration is a process all living organisms perform.
5. Conclude with correct roles: The roles of prokaryotes in the cycling of elements in an ecosystem include nitrogen fixation and decomposition, as these processes are directly linked to their biological functions.