Which of the following does NOT indicate microbe involvement in energy and nutrient flow?

• A. Photosynthesis by cyanobacteria
• B. Nitrogen fixation by Rhizobium species
• C. Decomposition of organic matter by fungi
• D. Formation of bone tissue in vertebrates

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the role of microbes in energy and nutrient flow. Microbes contribute by processes such as photosynthesis, nitrogen fixation, and decomposition, which recycle nutrients and produce energy-rich compounds.
2. Step 2: Analyze each option to see if it involves microbial activity related to energy or nutrient cycling. Photosynthesis by cyanobacteria converts light energy into chemical energy, contributing to energy flow.
3. Step 3: Nitrogen fixation by Rhizobium species converts atmospheric nitrogen into forms usable by plants, playing a key role in the nitrogen cycle and nutrient flow.
4. Step 4: Decomposition of organic matter by fungi breaks down dead material, releasing nutrients back into the environment, which is essential for nutrient cycling.
5. Step 5: Formation of bone tissue in vertebrates is a biological process carried out by animal cells, not microbes, and does not contribute to microbial involvement in energy or nutrient flow.