Examkin

Question

Difficulty: MediumBasic Ecological Concepts and Ecosystem Structure

In a freshwater pond ecosystem, bacteria and fungi decompose organic detritus on the pond bed, releasing inorganic nutrients into the water. Which ecological role best describes these microorganisms, and what is their primary contribution to ecosystem stability?

  1. Saprotrophs, by recycling essential inorganic nutrients back to primary producersAnswer
  2. B
    Primary consumers, by transferring kinetic energy from autotrophs to secondary consumers
  3. C
    Nitrifying autotrophs, by directly converting atmospheric nitrogen gas into organic protein compounds
  4. D
    Pioneer species, by initiating primary succession on bare uncolonized rock substrates

Answer

Saprotrophs, by recycling essential inorganic nutrients back to primary producers
Saprotrophic bacteria and fungi break down dead plant and animal detritus using extracellular enzymes. This process liberates inorganic mineral nutrients into the water column and substrate, making them available for reabsorption by photosynthetic autotrophs and thereby maintaining nutrient balance in the ecosystem.

Step-by-Step Solution

1
Identify the biological mode of nutrition of the organisms mentioned in the stem.
Organisms that feed on dead organic detritus via extracellular enzymatic breakdown are classified as saprotrophs (decomposers).
Establishing the correct ecological terminology for organic matter breakdown.
2
Determine their functional contribution to ecosystem structure.
Saprotrophic breakdown converts complex organic molecules into simple inorganic salts (such as nitrates and phosphates) that autotrophs require for photosynthesis.
Nutrient cycling is vital for continuous primary productivity and ecosystem sustainability.

Key Concept

Role of Decomposers (Saprotrophs) in Ecosystem Structure
Estimated Time:1m 0s
Rate this question

Topics

Basic Ecological Concepts and Ecosystem Structure

More questions from this topic