[Campbell Biology P.1187] Based on the hopping experiment data provided, what is the approxim... | Practice Question

Based on the hopping experiment data provided, what is the approximate energy cost per hop at the lower frequency 0.92 hops/sec compared to the higher frequency 1.85 hops/sec , after accounting for standing energy 159 joules/sec , and what does this difference suggest about energy storage in tendons?

  • A: The energy cost per hop is lower at the lower frequency (approx. 311 J/hop vs 605 J/hop), suggesting tendons are more efficient at slower movements.
  • B: The energy cost per hop is significantly higher at the lower frequency (approx. 605 J/hop) compared to the higher frequency (approx. 311 J/hop), suggesting that tendons are more effective at storing and releasing elastic energy at higher frequencies.
  • C: The total energy used per second decreases at lower frequencies, but the energy cost per hop increases, indicating a trade-off where lower frequency movements are less metabolically efficient per unit of movement.
  • D: The energy cost per hop is higher at the higher frequency (approx. 605 J/hop vs 311 J/hop), indicating that muscles have to work harder at faster paces.

Explanation

First, calculate the net energy used per second by subtracting the standing energy 159 J/sec from the total energy used: - For 1.85 hops/sec: 735 J/sec - 159 J/sec = 576 J/sec - For 0.92 hops/sec: 716 J/sec - 159 J/sec = 557 J/sec Next, calculate the energy cost per hop by dividing the net energy by the frequency: - For 1.85 hops/sec: 576 J/sec / 1.85 hops/sec ≈ 311.35 J/hop - For 0.92 hops/sec: 557 J/sec / 0.92 hops/sec ≈ 605.43 J/hop This shows that the energy cost per hop is significantly higher at the lower hopping frequency. This difference suggests that at higher frequencies, the tendons are more effectively utilized to store and release elastic energy, much like a spring. This elastic recoil reduces the metabolic energy cost per hop, making higher frequency hopping more energetically efficient per unit of movement. At lower frequencies, less elastic energy is recovered, requiring more active muscle work per hop.