With regard to energy flow in ecosystems, according to the Second Law of Thermodynamics, what percentage of energy is lost at every trophic level?

Correct option is A

• The Second Law of Thermodynamics states that energy transfer is inefficient, and with each transfer, a significant portion is lost as heat.
• In an ecosystem, energy flows through trophic levels in a food chain.
• Only about 10% of energy is transferred from one trophic level to the next, while 90% of the energy is lost mainly as heat, respiration, and metabolic processes.
• This is known as the "10% Law" proposed by Raymond Lindeman (1942).

• Producers (Plants) → Primary Consumers (Herbivores) → Secondary Consumers (Carnivores) → Tertiary Consumers (Top Predators).
• 90% of energy is lost at each step, leaving only 10% available to the next level.

• Heat Dissipation → Due to metabolic activities.
• Respiration → Used by organisms for survival.
• Movement & Growth → Energy spent on daily functions.

• Grass (1000 kcal) → Grasshopper (100 kcal) → Frog (10 kcal) → Snake (1 kcal).