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Quiz: Foundations of Ecology

Test your understanding of core ecological vocabulary and foundational science concepts with these review questions.

1. What does the Greek root word oikos in "ecology" mean?

  1. Life or living
  2. House or dwelling place
  3. Earth or ground
  4. Study or knowledge
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The correct answer is B. The word ecology comes from the Greek oikos, meaning "house" or "dwelling place," combined with logos, meaning "study of." So ecology literally means the study of where living things live and how they interact with their environment.

Concept Tested: Ecology

2. Which of the following is an example of an abiotic factor in an ecosystem?

  1. A mushroom decomposing a fallen log
  2. Bacteria in the soil breaking down organic matter
  3. The temperature of a freshwater stream
  4. A population of deer grazing in a meadow
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The correct answer is C. Abiotic factors are the nonliving components of an ecosystem, including sunlight, temperature, water, soil minerals, and wind. Temperature is a physical condition of the environment, not a living organism. The other options all describe biotic (living) factors.

Concept Tested: Abiotic Factors

3. What is the correct order of ecological organization from smallest to largest?

  1. Population, community, ecosystem, biome, biosphere
  2. Individual, population, ecosystem, community, biosphere
  3. Individual, community, population, ecosystem, biome
  4. Species, population, community, biome, ecosystem
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The correct answer is A. The levels of ecological organization from smallest to largest are: individual, population, community, ecosystem, biome, biosphere. Each level builds on the one below it, with new properties emerging at each scale. This answer begins at population and correctly sequences through to the biosphere.

Concept Tested: Population

4. How does a habitat differ from a niche?

  1. A habitat describes an organism's diet while a niche describes its predators
  2. A habitat is only found in aquatic environments while a niche applies to all environments
  3. A habitat is the physical place where an organism lives while a niche is its ecological role
  4. A habitat changes seasonally while a niche remains constant throughout the year
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The correct answer is C. A habitat is like an organism's address -- the physical place where it lives, defined mainly by abiotic factors like temperature, moisture, and soil type. A niche is like the organism's job description -- it includes what it eats, when it is active, how it interacts with other species, and its overall role in the ecosystem.

Concept Tested: Niche

5. What is the primary role of photosynthesis in an ecosystem?

  1. To break down dead organic matter and return nutrients to the soil
  2. To capture sunlight energy and convert it into chemical energy stored in glucose
  3. To release carbon dioxide into the atmosphere for other organisms to use
  4. To transfer heat energy from producers to consumers in the food web
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The correct answer is B. Photosynthesis is the process by which plants, algae, and some bacteria capture sunlight energy and convert it into chemical energy stored in organic molecules, primarily glucose. This process is the entry point for nearly all energy in nearly all ecosystems, making producers the foundation of food webs.

Concept Tested: Photosynthesis

6. Why is the fact that ice floats ecologically important?

  1. Floating ice increases water temperature, promoting faster algal growth
  2. Floating ice allows fish to breathe by trapping oxygen at the surface
  3. Floating ice insulates the water below, preventing lakes from freezing solid
  4. Floating ice reflects sunlight, which reduces photosynthesis in aquatic ecosystems
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The correct answer is C. Because solid water (ice) is less dense than liquid water, ice forms on the surface and acts as an insulating layer. This prevents lakes and ponds from freezing solid from the bottom up, which would kill aquatic organisms. This density anomaly is one of water's unique properties that makes aquatic ecosystems possible in cold climates.

Concept Tested: Water Properties

7. What distinguishes organic molecules from inorganic molecules?

  1. Organic molecules are found only in animals while inorganic molecules are found in plants
  2. Organic molecules dissolve in water while inorganic molecules do not
  3. Organic molecules are always larger than inorganic molecules
  4. Organic molecules are carbon-based and produced by living things while inorganic molecules generally are not
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The correct answer is D. Organic molecules are carbon-based molecules produced by living things or derived from once-living things, such as sugars, proteins, fats, and DNA. They store chemical energy in their carbon-hydrogen bonds. Inorganic molecules, like water, minerals, and atmospheric gases, are generally not carbon-based (with a few exceptions like CO2).

Concept Tested: Organic Molecules

  1. They are identical processes that occur in different organisms
  2. They are complementary processes where the products of one are the reactants of the other
  3. They both require sunlight to function and stop at night
  4. They both produce oxygen as their primary output
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The correct answer is B. Photosynthesis and cellular respiration form a complementary cycle. Photosynthesis uses carbon dioxide and water to produce glucose and oxygen, while cellular respiration uses glucose and oxygen to produce carbon dioxide, water, and usable energy (ATP). The outputs of each process become the inputs of the other, creating a continuous loop.

Concept Tested: Cellular Respiration

9. At which level of biodiversity would scientists measure the variety of genes within a wolf population?

  1. Genetic diversity
  2. Species diversity
  3. Ecosystem diversity
  4. Community diversity
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The correct answer is A. Genetic diversity refers to the variety of genes within a species or population. Measuring the variety of genes within a wolf population is an example of assessing genetic diversity. Greater genetic diversity gives a population more adaptability to changing conditions. Species diversity counts different species, and ecosystem diversity measures the variety of ecosystem types in a region.

Concept Tested: Biodiversity

10. Which question should you ask first when evaluating an ecological claim you see on social media?

  1. Does the claim use dramatic or emotional language
  2. How many people have shared the post
  3. Who is the source of the information
  4. Does the claim match your personal experience in nature
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The correct answer is C. When evaluating ecological claims, the first and most important question is to identify the source. Is it a peer-reviewed journal, a university, a government agency, or an anonymous social media account? Reliable sources with scientific credentials are far more likely to present accurate information than unverified accounts. Checking the source is the foundation of media literacy in science.

Concept Tested: Ecology