OpenSciEd 7.5 Ecosystem Dynamics Practice Test

These questions are part of the practice quiz. Start practicing

• Birth rates near carrying capacity tend to:
• Which soil process releases nitrogen for plant uptake?
• Where does primary ecological succession typically begin?
• What is nitrogen fixation, and why is it essential for ecosystems?
• What are the typical traits of early-successional (pioneer) species compared with late-successional species?
• Which example best illustrates adaptations that support survival under changing environmental conditions?
• Which term describes the ability of a system to maintain a constant state over time despite small disturbances?
• Which scenario would increase population size in a habitat?
• Which processes move essential elements through living and nonliving components of an ecosystem?
• In an experiment, what term describes the factor deliberately changed by the researcher to observe its effect?
• In an ecosystem, energy flows from producers to consumers and is eventually lost as heat; what is the role of nutrient cycles?
• Why do most real ecosystems resemble open systems?
• Which of the following are living components that can be producers, consumers, or decomposers?
• What happens to most energy as it moves from one trophic level to the next in an ecosystem?
• Which term means a standard by which something is judged or decided?
• How do abiotic factors such as temperature, water, and sunlight influence ecosystem structure and species distributions?
• What does ecological resilience mean?
• Which group includes producers, consumers, and decomposers?
• Which term describes an organism that can create its own food, usually through photosynthesis?
• How do decomposers affect nutrient availability in soil and plant growth?
• What processes drive the carbon cycle, and how do photosynthesis and respiration affect atmospheric CO2?
• What is the value of using models (such as food webs or energy pyramids) in understanding ecosystem dynamics?
• Which farming approach blends multiple crops, trees, livestock, and fish to create a diverse resource base?
• Which example illustrates a density-dependent factor affecting carrying capacity?
• Which term represents the types of consumers: herbivores, carnivores and omnivores?
• In identifying scientific categories, which term describes a system of living and non-living parts interacting in a specific area?
• Which organism can produce its own food, typically through photosynthesis, and is the base of the food chain?
• In experimental design, what term refers to the cause that scientists manipulate to observe effects?
• An organism, typically a herbivore, that directly feeds on producers and occupies the second trophic level in a food chain is a
• Which factor category includes climate, soil, water, light, altitude, and events?
• A species that is at risk of extinction across a significant portion or all of its range is described as?
• Compare a natural disturbance with an anthropogenic disturbance and their typical ecological impacts.
• Distinguish between energy flow and matter cycling as they occur in ecosystems, giving an example for each.
• What do disturbances do to ecosystems, and what does ecological resilience mean in this context?
• If resources decrease, what happens to populations?
• Which term describes continual change from one condition to another, with slight variation due to environmental factors?
• Which set correctly matches a type of symbiotic relationship with its example?
• Seasonal changes can cause shifts in predator-prey dynamics and resource availability. Which explanation best describes why this happens?
• How can predator-prey interactions influence the population dynamics of both species?
• Which action would help orangutans by increasing energy supply?
• A species that is in danger of extinction over a significant portion or all of its range is described as?
• What is the ultimate source of energy for most ecosystems?
• How does the water cycle intersect with ecosystem dynamics and energy flow?
• Describe how decomposers contribute to nutrient availability in soil and how this affects plant growth.
• Carrying capacity is most closely tied to which ecological concept?
• How do energy pyramids illustrate the decrease of usable energy at higher trophic levels?
• What is the role of pollinators in ecosystems and energy transfer?
• Which of the following are ecosystem services commonly provided by healthy ecosystems?
• What term describes the practice of growing a single crop year after year on the same land?
• How would you design an experiment to test whether the presence of a predator controls herbivore populations?
• How do ecosystem dynamics relate to human well-being and sustainability?
• List the main trophic levels in a typical ecosystem, starting with producers.
• What is a likely outcome if a keystone species is removed from an ecosystem?
• What term describes a pattern in a time series showing the general direction of change over time?
• Where does most energy go during cellular respiration, and how does this limit energy available to higher trophic levels?
• What role do migratory species play in ecosystem dynamics?
• What is a keystone species, and how can its removal affect an ecosystem?
• What is the purpose of energy pyramids in ecosystem studies?
• How can you interpret a population growth or decline graph for an ecosystem, and what factors might cause changes?
• Which statement best describes how photosynthesis contributes to energy input in ecosystems and what factors can limit it?
• Identify two environmental factors that can limit photosynthesis in an ecosystem.
• Differentiate between the carbon source and carbon sink, with an example of each.
• What are invasive species, and what consequences can they have on ecosystem dynamics?
• What is functional redundancy and how does it relate to resilience?
• Briefly describe how carbon moves through ecosystems via photosynthesis, respiration, and decomposition.
• Which term best describes an organism that can produce its own food using light, water, carbon dioxide and other chemicals?
• What is primary productivity, and how is it measured in ecosystems?
• Which of the following is an example of how human activity can affect ecosystem dynamics?
• What term describes a community of living organisms interacting with each other and their non-living environment within a specific area?
• Ecological disturbances are events that change an ecosystem, such as storms, floods, wildfires, or human activity. Which term describes these disturbances?
• In detritus-based ecosystems, which statement about detritus, detritivores, and decomposers is true?
• Which ecosystem service is most closely associated with recreational or cultural benefits?
• How do seasonal changes affect ecosystem dynamics, including productivity and species interactions?
• How do microhabitats within an ecosystem contribute to its stability and biodiversity?
• Which of the following best describes a carbon sink?
• What term refers to the non-living parts of an ecosystem like climate, soil, and water?
• Which statement is an example of mutualism?
• Which factors influence an ecosystem's resilience after a disturbance?
• Which trophic level contains the most energy in a typical ecosystem?
• What is the role of decomposers in ecosystems?
• What is the difference between primary productivity and secondary productivity in ecosystems?
• Why are phytoplankton considered a keystone component of many aquatic ecosystems?
• The number of orangutans that can live in a 1 km2 space?
• In an ecological experiment, which statement correctly describes the control and the experimental group?
• The number of individuals in an area of a specific size.
• Which organisms capture sunlight to begin energy transfer in most terrestrial ecosystems?
• Which process is part of matter cycling in ecosystems?
• Which term describes an organism that breaks down dead organisms and releases nutrients into the environment?
• A dense forest rich in biodiversity, found typically in tropical areas with consistently heavy rainfall.
• Which description correctly characterizes producers?
• Which statement best describes the role of photosynthesis in ecosystem energy flow?
• Why is biodiversity important for ecosystem functions?
• Provide an example of an invasive species and explain its potential impact on ecosystem dynamics.
• Which term refers to the living parts of an ecosystem?
• Which term refers to the variable measured to observe the effect, the outcome?
• How can competition influence resource use and species distribution?
• Gives orangutans more energy and increases their population.
• Explain the 10% rule in energy transfer between trophic levels and its ecological significance.
• Which nitrogen process converts atmospheric nitrogen into usable forms for organisms?
• Which term describes an organism that eats other plants or animals for energy and nutrients?
• Describe the water cycle's key processes and how they sustain life on Earth.
• What term describes the maximum population size that an environment can support over time?
• Which statement describes a density-dependent factor?
• How does secondary succession differ from primary, and what often starts secondary succession?
• An organism typically a carnivore or omnivore that eats primary consumers (herbivores) in a food chain is a
• How does redundancy in food webs contribute to ecosystem stability?
• What term describes when a population temporarily exceeds carrying capacity?
• What is a niche?
• How do biogeochemical cycles connect living organisms to rocks, air, and water in an ecosystem?
• Which term refers to a large agricultural estate focusing on crops?
• Explain the concept of ecosystem resilience, and what factors influence a system's ability to recover after a disturbance.
• Which statement describes disturbances that test an ecosystem's resilience?
• Which is an abiotic factor?
• If resources increase, populations increase.
• A forest that has been managed by communities for a long time and serves as important wildlife habitat is known as?
• Which term describes a group of objects that share important properties and are thought to be independent of human construction; used to classify objects to predict, explain, and control their behavior?
• How do weather and climate differ, and which has a stronger impact on ecosystem dynamics over time?
• In a freshwater pond, how do temperature and dissolved oxygen affect organisms and seasonal patterns?
• If an environment has a carrying capacity of 1000, what is the expected long-term population size?
• What term refers to the variety of living things in ecosystems around the world?
• Provide two common decomposers and the role each plays in the ecosystem.
• Which term means a limitation or restriction?
• What does an energy pyramid illustrate, and why is the pyramid shape typically widest at the bottom?
• What is the purpose of a control plot without predators in predator-prey experiments?
• The specific role and position of an organism within its environment is its
• Which statement best describes open versus closed ecosystems and why most real ecosystems resemble open systems?
• What is a detritivore, and how does it differ from a decomposer?
• What is the role of decomposers in nutrient cycling and ecosystem health?
• What consequence arises from excess fertilizer runoff increasing nitrates into water?
• What is an energy pyramid and what does it illustrate?
• What would be the most likely outcome of removing a keystone species?
• What is carrying capacity, and how can it be identified on a population growth curve?
• What is the term for the variety of all living things on Earth, including plants, animals, insects, and microbes?
• Which term best describes an organism that eats both plants and animals?
• Which scenario would likely decrease carrying capacity for a species in a region?
• What role do producers play in energy flow within an ecosystem?
• Differentiate between energy capture (photosynthesis) and energy use (metabolism) in producers.
• What is bioaccumulation, and how can it affect higher trophic level populations?
• Which statement best distinguishes predator-prey dynamics, competition, and symbiosis in shaping ecosystems?
• Which statement best matches the definition of a consumer?
• If a graph shows a decrease in the diversity index after a disturbance, what might this indicate about the ecosystem’s resilience?
• What happens when a population temporarily exceeds carrying capacity?
• What is the term for the number of individuals per unit area?
• What is a direct consequence of nitrate runoff on aquatic ecosystems?
• A large geographical area with a specific climate, vegetation, and life is called
• Design a simple controlled experiment to test how a limiting factor (for example, water) affects plant growth in an ecosystem context.
• What is a typical pattern of predator and prey population dynamics over time due to their interactions?
• What is the role of soil microorganisms in nutrient cycling and plant health?
• Approximately what percentage of energy is transferred from one trophic level to the next, and what happens to the rest?
• Which crop yields a lot of product on a small land area?
• How do producers contribute to the atmospheric carbon balance?
• Which process primarily releases CO2 back to the atmosphere?
• In an ecosystem dynamics investigation, what would be an appropriate control and an appropriate independent variable?
• Which two human activities are commonly cited as altering ecosystem dynamics, potentially reducing biodiversity and disrupting energy flow?
• Carrying capacity is defined as:
• Which statement describes how an invasive species can affect energy flow and nutrient cycling?
• The study of how to interact with the environment in a way that ensures future generations will have enough resources is called?
• How does energy flow differ from nutrient cycling in ecosystems?
• Which term best describes a disturbance that changes an ecosystem, such as storms or wildfires?
• Why is biodiversity important for ecosystem resilience?
• Why does biodiversity loss reduce resilience?
• What is a niche and how can two species coexist by occupying different ecological niches?
• Humans influence carrying capacity by:
• Which graph best represents logistic growth approaching carrying capacity?
• On a population growth curve, what does a plateau indicate?
• Which term means a principle or standard by which something may be judged or decided?
• Differentiate between gross and net primary production.
• In addition to releasing nutrients, how do decomposers contribute to soil formation?
• Which term best describes an organism that can make its own food using energy from the sun or chemicals?
• Which statement correctly contrasts a food chain and a food web?
• What best describes the transfer of energy between trophic levels?
• What is ecological succession and how do primary and secondary succession differ?
• How does photosynthesis connect to energy transfer in ecosystems?
• What is the term for a group of the same kind of organism living in a given area?
• Which term describes the process of changing land use, such as turning a forest into farmland or building a city?
• Which types of evidence can scientists use to study ecosystem dynamics, and why is multiple lines of evidence important?
• Which factor most directly limits carrying capacity?
• What is the effect of invasive species introduction on ecosystem dynamics?
• If energy transfer to the next trophic level is about 10%, which statement best explains what happens to the rest?
• Which pairing correctly identifies one biotic and one abiotic factor that can influence ecosystem dynamics?
• How do weather and climate differ, and how can each influence ecosystem dynamics?
• Orangutans need space to find enough food.
• Why is nitrogen important for ecosystems, and what processes cycle nitrogen through the environment?
• Define carrying capacity and explain how limiting factors determine it for a population.
• Name and briefly describe the three types of symbiotic relationships and give an example of each.
• Which statement best describes ecological resilience?
• An organism that eats animals to gain energy is a
• Which graph best represents logistic population growth as it approaches carrying capacity?
• What evidence would you look for to determine whether a population is near carrying capacity?
• What factor commonly slows population growth in an ecosystem?
• An animal that naturally preys on other animals is a
• An organism that breaks down dead material and recycles nutrients is called a
• Which of the following describes a potential ecosystem response to climate change?
• Which statement accurately describes energy transfer in an ecosystem's energy pyramid?
• Which statement about energy flow is correct?
• Who cuts rainforest and grows oil palms for money to better their lives?
• An organism that eats both plants and animals is called a
• Which field of study focuses on using environmental resources in a way that preserves them for future generations?
• Which statement best describes the role of climate regulation in ecosystems?
• What happens to the energy captured by producers through photosynthesis?
• Which factor is a common limiting factor for population growth in many ecosystems?
• Distinguish between energy flow and matter cycling in ecosystems.
• Which organism cannot produce its own food and must eat other organisms to obtain energy?
• Which process by phytoplankton contributes to global oxygen production and carbon cycling?
• If limiting factors reduce photosynthesis, what is the likely effect on the ecosystem's energy flow?
• How can the complexity of a food web influence ecosystem stability and resilience?
• As a population nears carrying capacity, what happens to its growth rate?
• In logistic growth, what is carrying capacity and why does it matter?
• An animal that eats plants to gain energy is a
• Which trophic level contains producers?
• Which term best describes the living components of an ecosystem, such as plants, animals, and microorganisms?
• How would you design a data table to compare the productivity of two ecosystems under different conditions?
• Which system uses a variety of crops, trees, livestock and fish to ensure a diverse food, fodder, and fiber supply?
• An animal that is caught and killed by another organism is called
• Why is only a portion of energy transferred from one trophic level to the next?
• Which concept refers to a group of objects that share important properties and are considered independent of human construction, used to classify objects to predict, explain, and control their behavior?
• Describe a real-world scenario where understanding ecosystem dynamics could inform conservation or management decisions.
• Why do keystone species have outsized effects on ecosystems relative to their abundance?
• Describe how models are used to predict ecosystem responses to disturbances such as drought or wildfire.
• What term refers to a species that no longer exists?
• Which two groups are most commonly responsible for decomposition and nutrient recycling in soils?
• What is one effect of ecosystem disturbances on energy flow and nutrient cycles?
• Which term describes the role and position of an organism within its environment, including resources used and interactions with other species?
• Which scenario best illustrates primary succession?
• Works for both humans and animals?
• How might climate change alter species distributions and ecosystem processes?
• How can scientists use experimentation and observation to evaluate claims about ecosystem changes due to climate change?
• How does a food web differ from a simple food chain?
• Fire acts as a natural disturbance in some ecosystems and affects succession.
• A group of the same kind of organism in an area.
• How do soils affect plant growth and ecosystem productivity?
• Which term describes the variable that researchers measure to determine the effect of changing the independent variable?
• Which crop produces a lot of product on a small land area?
• How can communities increase their carrying capacity?
• Describe the importance of primary producers in maintaining atmospheric oxygen levels.
• What process do decomposers use to release nutrients, and why is this process essential after a disturbance?
• What is the term for the process by which plants spread their seeds to new locations?
• In most ecosystems, which group forms the base of the energy pyramid?
• Provide an example of a carbon sink in an aquatic system and explain its significance.