An indicator species<span> is an organism whose presence, absence or abundance reflects a specific environmental condition. </span>Indicator species<span> can signal a change in the biological condition of a particular ecosystem, and thus may be used as a proxy to diagnose the health of an ecosystem.
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Answer: water
Explanation: Water is everywhere and required to survive, so water would be the most abundant compound.
Photosynthesis:
1) Reactants = CO2, Water, Sunlight
2) Products = O2, Glucose,
Cellular Respiration:
1) Reactants = O2, Glucose
2) Products = CO2, Energy (in ATP)
Hope this helps!
