Which of the following best describes a biotic environment?

Question

Which of the following best describes a biotic environment?

1. A. Air, water, and soil
2. B. Sunlight, temperature, and topography
3. C. Plants, animals, and microorganisms (Correct answer)
4. D. Minerals and rocks

Correct Answer

Option C — Plants, animals, and microorganisms

Detailed Solution & Explanation

The correct answer is Plants, animals, and microorganisms.

Key Points

• The biotic environment is the sum of all living organisms in a habitat together with their interactions — competition, predation, parasitism, mutualism and decomposition.
• Plants, animals and microorganisms covers the three functional groups completely: producers, consumers and decomposers.
• The rejected options are all abiotic:
  • air, water and soil are the physical media,
  • sunlight, temperature and topography are physical factors,
  • minerals and rocks are geological, non-living material.

Additional Information

• Only microorganisms close the nutrient loop. Without decomposers, nutrients would stay locked in dead biomass and the cycles of carbon, nitrogen and phosphorus would halt — which is why they belong in any complete statement of the biotic environment.
• Biotic interactions are classified by their effect on each partner: mutualism (+/+), commensalism (+/0), predation and parasitism (+/−), competition (−/−) and amensalism (−/0).
• Soil is a common trap in this topic. Soil as mineral matter is abiotic, but real soil is a composite that also contains living roots, bacteria, fungi and fauna, so questions usually specify which sense is meant.
• Together the biotic community and its abiotic surroundings form an ecosystem; the biotic part alone is the biocoenosis, and the physical part the biotope.