Q: According to the first law of thermodynamics, which equation correctly represents the conservation of energy in an ecosystem?

$$\text{Energy}_{\text{input}} = \text{Energy}_{\text{output}} + \text{Energy}_{\text{lost as heat}}$$

Q: Which equation best represents net primary production (NPP) in an ecosystem?

$$\text{NPP} = \text{GPP} - R$$

Q: Which equation best represents production efficiency (PE) in a consumer?

$$\text{PE} = \frac{\text{Net secondary production}}{\text{Assimilation of primary production}} \times 100\%$$

Question 1

Which statement best describes the flow of energy and cycling of matter in an ecosystem?

Accepted Answer

Energy flows one-way through the ecosystem, while matter cycles within it.

Question 2

According to the first law of thermodynamics, which equation correctly represents the conservation of energy in an ecosystem?

Accepted Answer

$$	ext{Energy}_{	ext{input}} = 	ext{Energy}_{	ext{output}} + 	ext{Energy}_{	ext{lost as heat}}$$

Question 3

Which of the following is a consequence of the second law of thermodynamics in ecosystems?

Accepted Answer

Every energy transfer increases the entropy of the universe, and some energy is lost as heat.

Question 4

Which equation best represents net primary production (NPP) in an ecosystem?

Accepted Answer

$$	ext{NPP} = 	ext{GPP} - R$$

Question 5

A forest ecosystem receives mineral nutrients from rainwater and loses nutrients through runoff. If the output of a mineral nutrient exceeds its input, what is the likely effect?

Accepted Answer

The nutrient will become a limiting factor for production.

Question 6

Which of the following organisms is classified as a detritivore?

Accepted Answer

A mushroom decomposing a dead tree.

Question 7

In aquatic ecosystems, which nutrient is most commonly limiting primary production?

Accepted Answer

Nitrogen

Question 8

Which adaptation allows plants to access limiting nutrients in terrestrial ecosystems?

Accepted Answer

Mutualisms with nitrogen-fixing bacteria

Question 9

Which equation best represents production efficiency (PE) in a consumer?

Accepted Answer

$$	ext{PE} = \frac{	ext{Net secondary production}}{	ext{Assimilation of primary production}} 	imes 100\%$$

Question 10

Why do birds and mammals have lower production efficiencies compared to insects?

Accepted Answer

They have higher costs of endothermy (maintaining body temperature).

Question 11

Which of the following best explains why eating meat is a less efficient way of tapping photosynthetic production?

Accepted Answer

Energy is lost at each trophic level, so less energy is available to top-level carnivores.

Question 12

Which process is responsible for converting atmospheric nitrogen ($$N_2) $$into a form usable by plants?

Accepted Answer

Nitrogen fixation

Question 13

Which biogeochemical cycle is most directly affected by burning fossil fuels?

Accepted Answer

Carbon cycle

Question 14

Which of the following is an example of bioremediation?

Accepted Answer

Introducing bacteria to metabolize toxic metals in polluted soil.

Question 15

Which ecosystem is most likely to have rapid decomposition and low nutrient levels in the soil?

Accepted Answer

Tropical rain forest

Question 16

What is the main biological importance of phosphorus in living organisms?

Accepted Answer

It is a component of ATP, nucleic acids, and bones.

Question 17

Which of the following best describes an open system in the context of ecosystems?

Accepted Answer

Both energy and matter are transferred between the ecosystem and its surroundings.

Question 18

A lake receives excess nitrogen and phosphorus from agricultural runoff, resulting in an algal bloom. What is the most likely consequence?

Accepted Answer

Depletion of oxygen due to increased decomposition, leading to fish die-offs.

Question 19

Which process in the water cycle is responsible for moving water from plants to the atmosphere?

Accepted Answer

Transpiration

Ecosystems and Energy: Dynamics, Productivity, and Nutrient Cycling

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