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WorksheetsEcosystems Unit Common Assessment
Total questions: 35
Worksheet time: 2hrs 45mins
What is a food web?
A diagram that shows the flow of energy through an ecosystem
A network of interconnected food chains in an ecosystem
A single path of energy flow in an ecosystem
A list of all the species in an ecosystem
Which of the following is an example of a natural disaster that can disrupt an ecosystem?
Deforestation
Earthquake
Urban development
Agriculture
How does human intervention typically impact the transfer of energy in food webs?
It always increases energy transfer efficiency
It can disrupt the balance and flow of energy
It has no impact on energy transfer
It simplifies the food web
Describe the process of primary succession.
It occurs in areas where no soil exists
It occurs in areas where soil is already present
It involves the re-establishment of a damaged ecosystem
It is the final stage of ecological succession
What is the main difference between primary and secondary succession?
Primary succession occurs faster than secondary succession
Primary succession starts with soil, secondary does not
Primary succession starts without soil, secondary starts with soil
There is no difference between them
Explain how secondary succession can affect species diversity.
It decreases species diversity permanently
It initially decreases diversity but can increase it over time
It has no effect on species diversity
It only increases species diversity
Why is biodiversity important for the stability of an ecosystem?
It reduces the number of species
It increases the ecosystem's resilience to changes
It makes the ecosystem more vulnerable to changes
It has no impact on ecosystem stability
Which of the following best describes ecological succession?
A sudden change in an ecosystem
A gradual process of change and replacement in an ecosystem
The extinction of species in an ecosystem
The introduction of new species into an ecosystem
How can population changes impact the energy flow in a food web?
They have no impact on energy flow
They can alter the balance of predator and prey relationships
They always increase energy flow
They simplify the food web
What role does biodiversity play in the health of organisms within an ecosystem?
It provides a variety of resources and habitats
It limits the resources available to organisms
It decreases the health of organisms
It has no role in organism health
Which of the following is a characteristic of a stable ecosystem?
Low species diversity
High species diversity
No species diversity
Constant species extinction
How does a natural disaster like a forest fire initiate secondary succession?
By creating new soil
By removing existing vegetation and allowing new growth
By introducing new species
By permanently destroying the ecosystem
What is the first stage of primary succession?
Establishment of a climax community
Colonization by pioneer species
Development of soil
Introduction of animals
In what way can human activity lead to secondary succession?
By planting trees in a barren area
By clearing land for agriculture
By introducing invasive species
By building urban areas
Why is it important to maintain biodiversity in ecosystems?
To ensure the survival of only the strongest species
To provide stability and resilience against environmental changes
To reduce the number of species
To simplify the food web
In the food web shown, the secondary consumer is (a) .
Final illustration (#8) shows (a)
As biodiversity increases, ecosystem stability (a)
In the energy pyramid, the organism with the least amount of energy available is the (a) .
A coal-burning facility is constructed in an area containing several pond ecosystems. How will this human activity most likely affect the pond ecosystems? (a)
Using the food web, choose the organisms in the correct order.
microscopic plants > water fleas > small fish > perch
microscope plants > perch > water flease > small fish
perch > waterboatmen > small fish > tadpoles
microscopic plants > tadpoles > water boatman > perch
As you move from the bottom of the energy pyramid to the top of the energy pyramid, the amount of energy available at each level—
Remains constant
Increases
Decreases, then increases
Decreases
What are two examples of organisms competing for biotic factors in an ecosystem? Choose two correct answers.
Tree species competing for sunlight in a dense rainforest
Elephants and leopards competing for water at a watering hole in Africa
Sharks in a marine ecosystem competing for a tuna food source
Sloths in a rainforest ecosystem competing for fresh water
Cheetahs in a grassland savanna competing for mates
Which best describes how organisms compete for resources in an ecosystem?
Organisms only compete for abiotic resources for survival.
Organisms only compete for biotic resources for survival.
Organisms compete for both biotic and abiotic resources in order to survive.
Organisms compete for abiotic resources after biotic resources disappear.
How could a hurricane negatively impact the transfer of energy within a food web? Select all that apply.
High winds could damage plant life such as trees and agriculture, which could weaken the patterns of energy transfer from producers to consumers.
The flooding could remove bacteria and contamination from the area, which could reduce certain diseases in plants and animals.
The flooding could cause destruction to the shelters of primary consumers, thus reducing the population and a food source for the organisms that prey on them.
The flooding could bring new fish to the coastal area, thus decreasing the transfer of energy from consumer to producer.
High winds could help the transfer of seeds to allow for seed dispersal and decrease the transfer of energy from producer to consumer.
Read the paragraph.
Hurricanes, floods, tornadoes, volcanoes, and wildfires are examples of ___________. If a wildfire occurs within a forest, the loss of vegetation leads to ______________. .Also, some organisms relocate to new areas, which leads to_____________ and a decrease in_______________ . All of these occurrences can affect the transfer of energy in a food web. Choose the option that identifies the missing terms or phrases, in order of appearance in the sentences.
population changes; overpopulation; ecosystem stability; primary succession
natural disasters; loss of habitat; changes in population size; food sources
natural disasters; overpopulation; changes in population size; primary succession
population changes; loss of habitat; ecosystem stability; food sources
Read the paragraph.
____________succession occurs when the land was not inhabited by any living organisms prior to the natural event or human activity that created the new habitat. This type of succession results in a(n) _____________ ecosystem. ______________succession occurs on land that was previously inhabited by living organisms. This type of succession results in a(n) ____________ecosystem.
Choose the option that identifies the missing terms, in order of appearance in the sentences.
Primary; stable; Secondary; unstable
Secondary; unstable; Primary; stable
Primary; stable; Secondary; stable
Secondary unstable; Primary; unstable
Suppose there is an oil spill because an oil company begins drilling on land. The oil spill destroys the nearby ecosystem. There are no longer any animals and plants inhabiting the area.
Which explanation best describes how succession occurs after the oil spill?
Primary succession will occur after algae and fungi begin to form. Plants will begin to grow, and animals will eventually repopulate the area. Biodiversity will increase.
Secondary succession will occur after lichen begins to form on bare rock. Plants and animals will then repopulate the area. Biodiversity will increase.
Primary succession will occur after existing seeds and roots grow new plant life. Biodiversity will decrease since the ecosystem will only contain producers.
Secondary succession will occur after animals repopulate the area. Plants will then begin to grow. Biodiversity will increase.
Read the paragraph.
Bees are vital to the ecosystem because they are the predominant pollinators of flowering plants in nature. Bees are considered a(n) _________________ because without them many plant populations would ______________- , and the ecosystem would be more ______________________ .
Choose the option that identifies the missing terms, in order of appearance in the sentences.
invasive species; increase; stable
pioneer species; stay the same; unstable
keystone species; decrease; unstable
native species; decrease; stable
A healthy ecosystem is one that has biodiversity to support life. Which of the following options best describe how biodiversity contributes to the stability and sustainability of an ecosystem? Select all that apply.
Biodiversity helps provide a variety of food sources for organisms which increases the stability of populations.
Biodiversity helps organism populations grow in their ecosystem by lowering birth rates in different populations.
Biodiversity helps ecosystems support animals that do not compete for food and stabilizes the populations of prey.
Biodiversity helps organisms create multiple predator and prey relationships, therefore helping to stabilize populations.
Look at this diagram of a food web.
In the diagram, which organism is the keystone species?
The vole, because it controls the stability of the plant populations.
The gray wolf, because it controls the stability of the entire food web.
The shrub with berries, because it controls the stability of the entire food web.
The elk, because it controls the stability of the shrubs and berries.
Suppose you are an ecologist investigating an ecosystem after a devastating natural event occurs. The area previously had been inhabited. Now, the environment has lost all animal species, as well as most plant species.
How will succession take place and what impact will it have? Choose two correct answers.
Secondary succession will restart from the existing soil, nutrients, and plant species in the ecosystem; plant diversity will increase.
Secondary succession will restart from the existing plant species in the ecosystem but plant diversity will decrease.
Since plant species diversity decreases, animals that depend on the plant species will leave the ecosystem to recover elsewhere.
Once plant species diversity increases, animal populations that depend on the plant species will begin to recover.]
Primary succession will restart from the existing soil, nutrients, and plant species in the ecosystem; plant diversity will increase.
The image shows an Amazon rainforest food web. How will a toucan being overhunted affect the transfer of energy in the food web? Choose the best response.
Overhunting toucans will only affect the boa constrictor and sloth populations because their food energy sources will increase. This will also increase the producer population.
Overhunting toucans will only affect the toucan and the boa constrictor. The boa constrictor will no longer have a main food energy source, and both populations will continue to decrease.
Overhunting toucans will only affect the toucan and the sloth. The sloth will not have the food to eat, causing a decrease in food energy for the sloth.
Overhunting toucans will affect the entire food web. Boa constrictors will rely more heavily on sloths as a main food energy source, causing a decrease in the sloth population. Producers may increase as a result.]
