Ecosystems: Interactions, Energy, and Dynamics | Online Learning Quizzes

Question 1

On newly exposed rock surfaces, primary succession occurs in a specific sequence. Which of the following represents the correct progression of ecological communities over time?

Accepted Answer

Pioneer species -> shrubs -> grasses -> trees

Answer

Grasses -> pioneer species -> shrubs -> trees

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Trees -> shrubs -> grasses -> pioneer species

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Shrubs -> trees -> pioneer species -> grasses

Question 2

Primary Succession

What is primary succession, and how do pioneer species initiate this process?

Accepted Answer

The establishment of an ecosystem on barren land, where pioneer species colonize and stabilize the environment.

Answer

The re-establishment of an ecosystem after a disturbance, starting with large trees.

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The final stage of succession, where pioneer species are replaced by climax species.

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A rapid process where the ecosystem is established without pioneer species.

Question 3

Imagine an invasive species is introduced into a local ecosystem. How might this impact the food web, competition for resources, and overall ecosystem balance?

Accepted Answer

The invasive species could disrupt the food web by preying on native species or competing for food resources.

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The invasive species could have no significant impact on the native ecosystem.

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The invasive species could enhance ecosystem balance by bringing new genetic material and increasing biodiversity.

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The invasive species could have no impact on competition for resources, as they typically target different resources than native species.

Question 4

In ecosystems, 'trophic levels' describe the feeding positions of organisms in the food web. Arrange these trophic levels in the correct order, starting with the organisms that make their own food:

Accepted Answer

Producers, Consumers, Decomposers

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Decomposers, Producers, Consumers

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Consumers, Producers, Decomposers

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Decomposers, Consumers, Producers

Question 5

How do scientists leverage technology to monitor ecosystems and guide conservation efforts?

Accepted Answer

Satellites track vegetation changes over time.

Accepted Answer

Drones observe animal populations in their habitats.

Accepted Answer

Sensors measure nutrient levels and pollutants in soil and water.

Question 6

How might climate change affect an ecosystem?

Accepted Answer

Change food webs and energy flow

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Increase biodiversity by expanding habitats

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Make ecosystems more stable and resilient

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Have no significant impact on ecosystems

Question 7

Scientists studied a species and noticed its population size fluctuated in a repeating pattern. What might explain this pattern, and how could it affect the ecosystem?

Accepted Answer

Seasonal changes in weather and food availability may influence the population cycle.

Accepted Answer

Competition with other species for resources and territory could contribute to the population cycle.

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The population cycle is likely a random occurrence with no specific cause.

Question 8

In an ecosystem, nutrient cycling refers to:

Accepted Answer

The continuous exchange of nutrients between living things and their surroundings, ensuring their availability for plant growth and ecosystem health.

Answer

The one-time transfer of nutrients from the environment to organisms, where they are stored permanently.

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A process limited to certain organisms, like plants, which can create their own nutrients using sunlight.

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A process that only happens in artificial or managed ecosystems, like farms and gardens.

Question 9

How does ecological succession contribute to the recovery of an ecosystem after a forest fire?

Accepted Answer

Pioneer species establish first, followed by shade-tolerant species, creating a diverse and stable ecosystem.

Answer

Shade-tolerant species dominate first, followed by pioneer species.

Answer

Succession is a one-time event that leads to an unchanging climax community.

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Ecological succession does not contribute to ecosystem recovery.

Question 10

How does biodiversity contribute to the stability and resilience of ecosystems? Give specific examples to support your answer.

Accepted Answer

Biodiversity provides a wider range of resources for different species, reducing competition and creating a more stable ecosystem.

Answer

Biodiversity increases competition among species, making ecosystems less stable and leading to the extinction of weaker species.

Answer

Biodiversity makes ecosystems more vulnerable to the introduction of invasive species, disrupting the natural balance.

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Biodiversity has no significant impact on ecosystem resilience and stability.

Question 11

Define a keystone species. Then, provide an example and explain how its loss can disrupt an ecosystem's balance.

Accepted Answer

A keystone species is a species that has a disproportionately large impact on its ecosystem relative to its abundance.

Answer

A keystone species is always the most abundant species in an ecosystem.

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The removal or decline of a keystone species has no noticeable effect on an ecosystem.

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Keystone species are exclusively top predators.

Question 12

In the food web diagram, which trophic level does the **Grasshopper** belong to?

Accepted Answer

Primary Consumer (Herbivore)

Answer

Producer (Plants)

Answer

Secondary Consumer (Carnivore)

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Tertiary Consumer (Top Predator)

Question 13

What is carrying capacity and how does it affect the stability and size of populations in an ecosystem?

Accepted Answer

Carrying capacity is the maximum number of individuals of a species that an environment can support indefinitely.

Answer

Carrying capacity is the minimum number of individuals needed for a population to survive.

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Carrying capacity is the average number of individuals in a population.

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Carrying capacity is the rate at which a population grows or declines.

Question 14

Which of these is NOT a component of an ecosystem?

Accepted Answer

Borders defined by humans

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Living organisms

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Non-living factors

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Energy flow

Question 15

In a food chain, which organism typically occupies the highest trophic level?

Accepted Answer

Animals that eat other animals

Answer

Plants

Answer

Animals that eat plants

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Organisms that break down dead matter

Question 16

Which type of relationship between species benefits both parties involved?

Accepted Answer

Mutualism

Answer

Parasitism

Answer

Commensalism

Answer

Competition

Question 17

What is the primary source of energy for most ecosystems on Earth?

Accepted Answer

The sun

Answer

Chemical reactions

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The wind

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Heat from the Earth's core

Question 18

What do we call a group of organisms of the same species that live in the same area?

Accepted Answer

Population

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Community

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Ecosystem

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Biome

Question 19

Which component is NOT found in an ecosystem?

Accepted Answer

Celestial bodies

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Producers

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Consumers

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Decomposers

Question 20

How does energy initially enter an ecosystem?

Accepted Answer

Photosynthesis

Answer

Cellular respiration

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Decomposition

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Evaporation

Question 21

Which organism in the following list is an herbivore?

Accepted Answer

Rabbit

Answer

Bear

Answer

Fox

Answer

Grass

Question 22

What is the primary function of decomposers in an ecosystem?

Accepted Answer

Recycling nutrients back into the environment

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Producing nourishment for other organisms

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Controlling predator populations

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Generating oxygen

Question 23

Which human activity is a significant threat to ecosystems?

Accepted Answer

Pollution

Answer

Conservation efforts

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Reforestation

Answer

Recycling

Question 24

What type of diagram illustrates the interconnected feeding relationships within an ecosystem?

Accepted Answer

Food web

Answer

Food pyramid

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Trophic level diagram

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Energy cascade diagram

Question 25

Which organism is an example of a keystone species?

Accepted Answer

Sea otter

Answer

Tiger

Answer

Grass

Answer

Bacteria

Question 26

In an ecosystem's food chain, which organisms are responsible for producing their own food from inorganic matter?

Accepted Answer

Producers (Autotrophs)

Answer

Consumers (Heterotrophs)

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Decomposers

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Top predators

Question 27

Which of these best depicts a food web?

Accepted Answer

A diagram illustrating the feeding connections within an ecosystem

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A simple chain linking organisms based on who eats whom

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A table summarizing the energy content of different organisms

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A graph showing fluctuations in species populations over time

Question 28

Which process converts light energy from the sun into chemical energy?

Accepted Answer

Photosynthesis

Answer

Respiration

Answer

Fermentation

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Combustion

Question 29

Which of the following is not considered a limiting factor in ecosystems?

Accepted Answer

Mutualistic interactions

Answer

Water availability

Answer

Sunlight intensity

Answer

Inter-species competition

Question 30

Which of the following is a renewable energy source?

Accepted Answer

Solar power

Answer

Coal

Answer

Natural gas

Answer

Nuclear energy

Question 31

Which process releases nutrients back into the soil?

Accepted Answer

Decomposition

Answer

Nitrification

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Assimilation

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Eutrophication

Question 32

Which type of relationship benefits both participating species?

Accepted Answer

Mutualism

Answer

Competition

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Parasitism

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Commensalism

Question 33

Who developed the theory of evolution through natural selection?

Accepted Answer

Charles Darwin

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Gregor Mendel

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Louis Pasteur

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Isaac Newton

Question 34

Which symbiotic relationship involves one organism benefiting while the other remains unaffected?

Accepted Answer

Commensalism

Answer

Mutualism

Answer

Parasitism

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Competition

Question 35

In a food chain, what organisms are the initial source of energy production?

Accepted Answer

Autotrophs

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Herbivores

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Carnivores

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Omnivores

Question 36

Describe the direction of energy flow through an ecosystem.

Accepted Answer

One-way from the sun to consumers

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Circular from consumers to producers

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Multi-directional depending on the ecosystem

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Only occurs during daylight hours

Question 37

Explain the term 'carrying capacity' in ecology.

Accepted Answer

The maximum population size an ecosystem can sustain indefinitely

Answer

The rate at which a population grows over time

Answer

The number of individuals currently present in a population

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The average age of individuals within a population

Question 38

Provide an example of an organism that plays the role of a producer in an ecosystem.

Accepted Answer

Grass

Answer

Deer

Answer

Bacteria

Answer

Fungus

Question 39

What type of event can significantly alter the structure and function of an ecosystem?

Accepted Answer

Ecological disturbance

Answer

Succession

Answer

Climax community

Answer

Pioneer species

Question 40

Which of the following is a plant that produces its own food through photosynthesis?

Accepted Answer

Grass

Answer

Hawk

Answer

Deer

Answer

Wolf

Question 41

A keystone species is one that:

Accepted Answer

Has a significant impact on the ecosystem despite its small size or numbers

Answer

Is found in abundance throughout the ecosystem

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Is at the top of the food chain

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Is currently threatened or endangered

Question 42

The process by which green plants use sunlight to produce energy is called:

Accepted Answer

Photosynthesis

Answer

Respiration

Answer

Chemosynthesis

Answer

Aerobic fermentation

Question 43

The carrying capacity of an ecosystem refers to the:

Accepted Answer

Maximum number of organisms that can be supported indefinitely

Answer

Rate at which organisms are born or die

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Amount of food available in the ecosystem

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Boundaries of the ecosystem

Question 44

In a food chain, the primary consumer is the organism that:

Accepted Answer

Eats plants

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Produces its own food

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Eats other animals

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Decomposes organic matter

Question 45

Which of the following is not a living component (biotic factor) of an ecosystem?

Accepted Answer

Sunlight

Answer

Plants

Answer

Animals

Answer

Bacteria

Question 46

In a food chain, which organism is always the first level?

Accepted Answer

Producers (plants)

Answer

Herbivores

Answer

Carnivores

Answer

Decomposers

Question 47

Which process captures the energy from the sun and converts it into food (chemical energy)?

Accepted Answer

Photosynthesis

Answer

Respiration

Answer

Decomposition

Answer

Transpiration

Question 48

What is the main role of decomposers in an ecosystem?

Accepted Answer

Break down dead plants and animals

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Produce food for other organisms

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Release oxygen into the atmosphere

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Control populations of herbivores

Question 49

What is the term for the network of interconnected food chains within an ecosystem?

Accepted Answer

Food web

Answer

Food chain

Answer

Ecosystem

Answer

Community

Question 50

What is the term for the gradual change in the composition of an ecosystem over time?

Accepted Answer

Ecological succession

Answer

Evolution

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Adaptation

Answer

Mutation

Question 51

How does the concept of carrying capacity relate to the stability of an ecosystem?

Accepted Answer

It is the maximum number of organisms an environment can support over time

Answer

It explains why populations fluctuate seasonally

Answer

It predicts the rate of extinction

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It measures the amount of energy in an ecosystem

Question 52

In a food chain, the organism typically at the first level is a:

Accepted Answer

Producer

Answer

Primary consumer

Answer

Secondary consumer

Answer

Tertiary consumer

Question 53

A symbiotic relationship where both species benefit is called:

Accepted Answer

Mutualism

Answer

Commensalism

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Parasitism

Answer

Predation

Question 54

The difference between a population and a community is that a:

Accepted Answer

Population is made up of the same species, while a community is made up of different species.

Answer

Community is made up of the same species, while a population is made up of different species.

Answer

Population is smaller than a community.

Answer

Community is smaller than a population.

Question 55

How do abiotic factors like temperature, rainfall, and sunlight influence the types of plants that grow in an ecosystem?

Accepted Answer

Abiotic factors influence plant growth by affecting processes like photosynthesis, seed sprouting, and water availability.

Answer

Abiotic factors mainly determine where plants grow, not how well they grow.

Answer

Abiotic factors have little effect on the kinds of plants found in an ecosystem.

Answer

Temperature and rainfall are the only abiotic factors that affect plant communities.

Question 56

In a forest ecosystem, decomposers perform a critical function. What is it?

Accepted Answer

Break down organic matter, releasing nutrients back into the ecosystem

Answer

Convert inorganic compounds into organic compounds

Answer

Consume producers and convert them into energy

Question 57

In an agricultural ecosystem, which practice best reduces soil erosion, prevents nutrient loss, and sustains crop yields?

Accepted Answer

Rotating crops and planting cover crops

Answer

Clearing forests for more farmland

Answer

Using more chemical pesticides

Answer

Applying excessive synthetic fertilizers

Question 58

Through which process does energy primarily enter an ecosystem?

Accepted Answer

Photosynthesis

Answer

Respiration

Answer

Trophic transfer

Answer

Decomposition

Question 59

Which organism usually occupies the first level of a food chain?

Accepted Answer

Producer

Answer

Herbivore

Answer

Carnivore

Answer

Omnivore

Question 60

What type of relationship is characterized by one organism capturing and consuming another?

Accepted Answer

Predation

Answer

Mutualism

Answer

Commensalism

Answer

Competition

Question 61

Which example best illustrates a keystone species?

Accepted Answer

Sea otter

Answer

Barnacle

Answer

Dolphin

Answer

Ant

Question 62

How are primary and secondary consumers distinguished in a food web?

Accepted Answer

Primary consumers feed on plants, while secondary consumers feed on meat.

Answer

Primary consumers feed on meat, while secondary consumers feed on plants.

Answer

Primary consumers are herbivores, while secondary consumers are carnivores.

Answer

There is no distinction between primary and secondary consumers.

Question 63

How does biodiversity contribute to the resilience of ecosystems?

Accepted Answer

Enhances resistance to environmental changes.

Answer

Reduces competition among species.

Answer

Facilitates the establishment of invasive species.

Answer

Has no impact on ecosystem stability.

Question 64

What is the primary role of decomposers in an ecosystem?

Accepted Answer

Decompose deceased organisms

Answer

Produce oxygen

Answer

Consume sunlight

Answer

Regulate water flow