Relationship between photosynthesis and respiration Original Scenario-Based Practice

Questions

1. 1.

   On the orbital bio-sanctuary Aethelgard, astrobiologists sealed an engineered bioluminescent moss and a colony of small aerobic herbivores inside a completely transparent, airtight habitat sphere supplied with regulated illumination. After several weeks, telemetry sensors recorded that atmospheric oxygen and carbon dioxide levels remained balanced and steady, allowing both species to flourish without replenishing any gases. Which statement best explains the metabolic relationship that enables this sealed ecosystem to persist?

   • A) The oxygen and organic sugars generated through photosynthesis serve as essential reactants for cellular respiration, while the carbon dioxide and water released by respiration supply the necessary substrates for photosynthesis.
   • B) The moss converts light energy into atmospheric ATP that directly powers the metabolic activities of the herbivores, while respiration releases photonic energy to sustain photosynthesis.
   • C) Both the moss and the herbivores independently fix free atmospheric nitrogen into carbohydrates, removing any biochemical dependence on reciprocal gas exchange.
   • D) Aerobic respiration consumes carbon dioxide and generates molecular oxygen, precisely offsetting the moss's consumption of oxygen during the Calvin cycle.

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