1. Ecosystems

Energy Flow — Quiz

Test your understanding of energy flow with 5 practice questions.

Practice Questions

Question 1

Which law of thermodynamics states that energy cannot be created or destroyed, only transformed?

Question 2

According to the Second Law of Thermodynamics applied to ecosystems, during energy transformations some energy is always converted into what unusable form?

Question 3

If in a forest ecosystem, gross primary productivity (GPP) is 30,000 kJ/m²/year and autotrophic respiration is 10,000 kJ/m²/year, what is the net primary productivity (NPP)?

Question 4

In an ecosystem where producers fix 50,000 kJ of energy and ecological efficiency is 10% per trophic level, how much energy (in kJ) is available to tertiary consumers?

Question 5

A food chain consists of phytoplankton → zooplankton → small fish → big fish. If phytoplankton contain 10,000 kcal, how much energy (in kcal) is available to the small fish (secondary consumers) under the 10% rule?