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AP Environmental Science Ecosystems — practice questions

Explore 23 free Ecosystems questions in AP Environmental Science Biology. Open each question or exercise to read its content, reference answers and available explanation.

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Ecosystems questions and exercises with answers

Showing questions 1–23 of 23.

Two parameters describe how an ecosystem copes with disturbance. What are they?Read the answer and worked solution →Roughly what share of all photosynthesis on Earth is carried out by phytoplankton?Read the answer and worked solution →What does a food chain describe?Read the answer and worked solution →What name is given to the organism at the very top of a food chain?Read the answer and worked solution →Food webs describe real ecosystems better, so why do ecologists still use food chains?Read the answer and worked solution →What sits at the base of a detrital food web?Read the answer and worked solution →What energy source does a chemoautotroph use?Read the answer and worked solution →No sunlight reaches a deep hydrothermal vent, yet a rich community lives there. What supports it?Read the answer and worked solution →In the Silver Springs ecosystem, roughly what fraction of the energy passed from the producers to the primary consumers?Read the answer and worked solution →How does net production efficiency compare between cold blooded and warm blooded animals?Read the answer and worked solution →Pyramids of numbers and of biomass can both be inverted. What about pyramids of energy?Read the answer and worked solution →What is the recycling of inorganic matter between organisms and their environment called?Read the answer and worked solution →What does the residence time of a water molecule measure?Read the answer and worked solution →In which chemical form is most of the carbon in the ocean found?Read the answer and worked solution →Nitrogen gas makes up most of the air, yet plants cannot use it directly. What brings nitrogen into living things?Read the answer and worked solution →Fertilizer washes off farmland and into a river mouth. Which process follows?Read the answer and worked solution →How long does the average phosphate ion stay in the ocean?Read the answer and worked solution →One of the worst dead zones lies off the coast of the United States. Which river basin feeds it?Read the answer and worked solution →Burning coal releases sulfur compounds into the air. What does rain falling through them become?Read the answer and worked solution →Chesapeake Bay oyster reefs covered more than 200,000 acres in the 1700s. Roughly what area remains?Read the answer and worked solution →Drop each fact by its elementRead the answer and worked solution →Knock out the false energy claimsRead the answer and worked solution →Tap the nitrogen path in orderRead the answer and worked solution →

Worked practice questions

Two parameters describe how an ecosystem copes with disturbance. What are they?

  1. Resistance and residence
  2. Resistance and resilience
  3. Resilience and richness
  4. Richness and residence
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Correct answer: B. Resistance and resilience

1. Equilibrium is the steady state where organisms are in balance with each other and their surroundings. 2. Resistance measures how well an ecosystem stays at equilibrium despite a disturbance. 3. Resilience measures how fast it returns to equilibrium once disturbed. 4. An ecosystem pushed far enough can lose its resilience entirely and never recover. _Source: OpenStax Biology 1e (CC BY 4.0), Chs 44 and 46, section 46.1 Ecology of Ecosystems_

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Roughly what share of all photosynthesis on Earth is carried out by phytoplankton?

  1. About 75 percent
  2. About 10 percent
  3. About 2 percent
  4. About 40 percent
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Correct answer: D. About 40 percent

1. Ocean ecosystems are the most common type on the planet. 2. The shallow ocean and the deep ocean surface hold enormous numbers of phytoplankton. 3. Those phytoplankton carry out about 40 percent of all photosynthesis on Earth. 4. That is why these environments matter so much to every aerobic organism. 5. The 75 percent figure is the share of the surface the oceans cover, not their share of photosynthesis. _Source: OpenStax Biology 1e (CC BY 4.0), Chs 44 and 46, section 46.1 Ecology of Ecosystems_

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What does a food chain describe?

  1. A branching web of feeding links
  2. A single line of feeding links
  3. A map of the habitats in an area
  4. A list of all species in an area
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Correct answer: B. A single line of feeding links

1. A food chain is a linear sequence through which energy and nutrients pass. 2. There is a single path from producers up through the consumers. 3. Each organism along it occupies a trophic level. 4. A branching arrangement with many links is a food web, which is a different model. _Source: OpenStax Biology 1e (CC BY 4.0), Chs 44 and 46, section 46.1 Ecology of Ecosystems_

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More Biology topics

Ecology and the Biosphere