In an ecosystem, which statement about energy flow is correct?

In an ecosystem, which statement about energy flow is correct?

• A. Producers fix energy through photosynthesis.
• B. Secondary consumers produce energy via photosynthesis.
• C. Decomposers do not recycle nutrients.
• D. Energy increases at higher trophic levels.

Answer: (A)

At the base of any ecosystem, energy comes from producers that convert sunlight into chemical energy through photosynthesis. Plants and other photosynthesizers capture light energy and store it as chemical energy in sugars and other organic molecules. This chemical energy then moves up the food chain as organisms eat those producers and each other, but only a portion is passed on at each step—the rest is used for the organisms’ metabolism or lost as heat. That’s why energy tends to decrease as you move to higher trophic levels. So, producers fixing energy through photosynthesis is why this statement is correct. Secondary consumers don’t produce energy by photosynthesis because they are not photosynthetic; decomposers recycle nutrients by breaking down dead material, not by stopping energy flow; and energy does not increase at higher trophic levels due to energy losses in transfer.

At the base of any ecosystem, energy comes from producers that convert sunlight into chemical energy through photosynthesis. Plants and other photosynthesizers capture light energy and store it as chemical energy in sugars and other organic molecules. This chemical energy then moves up the food chain as organisms eat those producers and each other, but only a portion is passed on at each step—the rest is used for the organisms’ metabolism or lost as heat. That’s why energy tends to decrease as you move to higher trophic levels.

So, producers fixing energy through photosynthesis is why this statement is correct. Secondary consumers don’t produce energy by photosynthesis because they are not photosynthetic; decomposers recycle nutrients by breaking down dead material, not by stopping energy flow; and energy does not increase at higher trophic levels due to energy losses in transfer.