Q: Gross primary production (GPP) and net primary production (NPP) are important measures in ecosystem ecology. Which equation correctly relates these terms?

$$\mathrm{GPP} = \mathrm{NPP} + \text{respiration}$$

Q: A caterpillar eats a leaf containing 100 J of energy. It uses 33 J for cellular respiration, incorporates 17 J into new biomass, and excretes 50 J as waste. What is the caterpillar's production efficiency?

$$\frac{17}{(17 + 33)} \times 100\% = 34\%$$

Question 1

Which of the following best explains why large carnivores, such as lions, are rare in most ecosystems?

Accepted Answer

Energy transfer between trophic levels is inefficient, so less energy is available to support organisms at higher trophic levels.

Question 2

According to the second law of thermodynamics, what happens to energy as it is transferred through trophic levels in an ecosystem?

Accepted Answer

Some energy is lost as heat at each transfer, increasing entropy.

Question 3

Which of the following statements correctly distinguishes between energy flow and matter cycling in ecosystems?

Accepted Answer

Energy flows through ecosystems and is eventually lost as heat, while matter cycles within ecosystems.

Question 4

Gross primary production (GPP) and net primary production (NPP) are important measures in ecosystem ecology. Which equation correctly relates these terms?

Accepted Answer

$$\mathrm{GPP} = \mathrm{NPP} + 	ext{respiration}$$

Question 5

In aquatic ecosystems, which factor most commonly limits primary production?

Accepted Answer

Light and nutrient availability, especially nitrogen and phosphorus

Question 6

A caterpillar eats a leaf containing 100 J of energy. It uses 33 J for cellular respiration, incorporates 17 J into new biomass, and excretes 50 J as waste. What is the caterpillar's production efficiency?

Accepted Answer

$$\frac{17}{(17 + 33)} 	imes 100\% = 34\%$$

Question 7

Why is trophic efficiency typically lower than production efficiency in ecosystems?

Accepted Answer

Trophic efficiency includes losses due to respiration, waste, and energy not consumed or assimilated at each trophic level.

Question 8

Which of the following best describes the role of decomposers in biogeochemical cycles?

Accepted Answer

They break down dead organisms, releasing nutrients back into the environment.

Question 9

In the context of the carbon cycle, which process is responsible for moving carbon from the atmosphere into living organisms?

Accepted Answer

Photosynthesis

Question 10

The Hubbard Brook Experimental Forest study demonstrated that deforestation leads to which of the following outcomes?

Accepted Answer

Increased loss of nutrients, such as nitrates, from the ecosystem

Question 11

Which of the following adaptations helps plants reduce the effects of nutrient limitations in terrestrial ecosystems?

Accepted Answer

Symbiotic relationships with nitrogen-fixing bacteria

Question 12

Which of the following best defines net ecosystem production (NEP)?

Accepted Answer

The gross primary production minus the energy used by all organisms for respiration

Question 13

Which of the following is an example of bioaugmentation in restoration ecology?

Accepted Answer

Introducing beneficial microbes to enhance nutrient cycling

Question 14

Why might a biomass pyramid be inverted in some aquatic ecosystems?

Accepted Answer

Primary producers, such as phytoplankton, have high turnover rates and are consumed rapidly.

Question 15

Which of the following equations correctly represents the law of conservation of mass as applied to ecosystems?

Accepted Answer

$$	ext{Total mass of inputs} = 	ext{Total mass of outputs}$$

Question 16

Which process in the nitrogen cycle converts atmospheric nitrogen ($$N_2) $$into a form usable by plants?

Accepted Answer

Nitrogen fixation

Question 17

A field receives 1000 J of sunlight. Plants capture 100 J as GPP, use 60 J for respiration, and herbivores consume 20 J. What is the net primary production (NPP) and what percentage of sunlight does it represent?

Accepted Answer

$$\mathrm{NPP} = 40\,J;\ \frac{40}{1000} 	imes 100\% = 4\%$$

Question 18

Which of the following best describes the difference between detritivores and decomposers?

Accepted Answer

Detritivores consume dead organic matter, while decomposers chemically break it down.

Question 19

Which of the following is a key lesson from the Hubbard Brook Experimental Forest regarding nutrient cycling?

Accepted Answer

Vegetation plays a critical role in retaining nutrients within an ecosystem.

Question 20

Which of the following is an example of bioremediation?

Accepted Answer

Using bacteria to break down oil spills in contaminated soil

Guided Study for Chapter 42: Ecosystems and Energy (AP Biology) MY VERSION

Study Guide - Practice Questions

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