State the first and second laws of thermodynamics as they apply to energy transformations in ecosystems.

State the first and second laws of thermodynamics as they apply to energy transformations in ecosystems.

• A. First law: energy is conserved, transformed not created or destroyed. Second law: energy transformations increase entropy; only a portion becomes work.
• B. First law: energy can be created; Second law: entropy always decreases.
• C. First law: energy is destroyed in transformations; Second: all energy becomes work.
• D. First law and second law both say energy cannot be transformed.

Answer: (A)

The key idea here is how energy behaves in ecosystems according to thermodynamics. The first law says energy cannot be created or destroyed in transformations; it only changes form. In ecosystems, light from the sun is captured by plants and turned into chemical energy, which then moves through the food web as organisms eat one another. The total amount of energy remains the same, even though its form changes from light to chemical energy to heat and biomass. The second law adds that each energy transformation increases disorder (entropy) and that not all energy can be converted into usable work. In practice, organisms use only a portion of the energy they obtain for growth and activities; the rest is dissipated as heat to the surroundings. This explains why energy flow through ecosystems is hierarchical and inefficient: energy enters as sunlight, a large portion is lost as heat at each transfer, and only a fraction is stored as biomass for the next trophic level. Other statements contradict these principles: energy cannot be created or destroyed or transformed into usable work with 100% efficiency, and entropy does not decrease in natural processes. This makes the first option the best description of how energy transformations operate in ecosystems.

The key idea here is how energy behaves in ecosystems according to thermodynamics. The first law says energy cannot be created or destroyed in transformations; it only changes form. In ecosystems, light from the sun is captured by plants and turned into chemical energy, which then moves through the food web as organisms eat one another. The total amount of energy remains the same, even though its form changes from light to chemical energy to heat and biomass.

The second law adds that each energy transformation increases disorder (entropy) and that not all energy can be converted into usable work. In practice, organisms use only a portion of the energy they obtain for growth and activities; the rest is dissipated as heat to the surroundings. This explains why energy flow through ecosystems is hierarchical and inefficient: energy enters as sunlight, a large portion is lost as heat at each transfer, and only a fraction is stored as biomass for the next trophic level.

Other statements contradict these principles: energy cannot be created or destroyed or transformed into usable work with 100% efficiency, and entropy does not decrease in natural processes. This makes the first option the best description of how energy transformations operate in ecosystems.