Primary and Secondary Productivity — Prelims Questions

Which of the following statements correctly defines Net Primary Productivity (NPP)?

If the Gross Primary Productivity (GPP) of an ecosystem is $2000\,\text{kcal m}^{-2} \text{yr}^{-1}$ and the producers' respiratory losses are $500\,\text{kcal m}^{-2} \text{yr}^{-1}$, what is the Net Primary Productivity (NPP)?

Which of the following ecosystems generally exhibits the highest Net Primary Productivity (NPP) per unit area?

According to the 10% law of energy transfer, if producers in an ecosystem have $10,000\,\text{J}$ of energy, how much energy would typically be available to the secondary consumers?

Which of the following statements is INCORRECT regarding secondary productivity?

Which of the following factors is LEAST likely to directly limit primary productivity in a tropical rainforest?