Question

Which one of the following represents the abundance of the organisms found in soil?

• A. ( Fungi>Aerobic bacteria>Anaerobic bacteria )
• B. ( Aerobic bacteria>Fungi>Anaerobic bacteria )
• C. ( Aerobic bacteria>Anaerobic bacteria>Fungi )
• D. ( Anaerobic bacteria>Aerobic bacteria>Fungi )

Hint:

Soil health and quality assessments often involve measuring the microbial balance, including the ratios of aerobic to anaerobic bacteria, to understand soil fertility and ecosystem functioning.

Answer 1

The Correct Option is C

The distribution and abundance of organisms in soil depend largely on oxygen availability, organic matter content, and moisture, among other environmental factors. Analysis of Each Option: (A) Fungi>Aerobic bacteria>Anaerobic bacteria: Incorrect. While fungi are abundant in soil, aerobic bacteria typically outnumber them due to their rapid growth rates and versatility in using soil organic matter. (B) Aerobic bacteria>Fungi>Anaerobic bacteria: This option is close but underestimates the abundance of anaerobic bacteria in certain soil types, especially those rich in organic materials where oxygen depletion can occur. (C) Aerobic bacteria>Anaerobic bacteria>Fungi: Correct. Aerobic bacteria are generally the most abundant due to their ability to rapidly utilize oxygen for metabolism. Anaerobic bacteria, while less abundant than aerobic types, can thrive in microenvironments within the soil where oxygen is limited. Fungi, although widespread and important, are generally less abundant than bacteria. (D) Anaerobic bacteria>Aerobic bacteria>Fungi: Incorrect. This arrangement overestimates the prevalence of anaerobic bacteria which, while significant, are typically not more abundant than aerobic bacteria in most soils. Conclusion:
Explanation: Aerobic bacteria dominate in most soils because they can efficiently exploit the most readily available form of carbon and energy under oxic conditions. Anaerobic bacteria adapt to niche environments where oxygen is depleted, and fungi, although essential for decomposing complex organics, rank lower in overall abundance compared to bacteria.