Ecosystem Balance and Keystone Species

3.2.1 h - Identify which of the following is NOT an example of a role of a key stone species in an ecosystem.

• maintains biodiversity

• controls populations

• provides critical resources for a wide range of species

• maintains balance of ecological relationships

• reduces the resilience of ecosystems

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NGSS.MS-LS2-4

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3.2.1 h - Identify which of the following best defines the term keystone species (from the syllabus)?

• a plant or animal that plays a unique and crucial role in the way an ecosystem functions.

• any organism that creates, significantly modifies, maintains or destroys a habitat. These organisms can have a large impact on the species richness and landscape-level heterogeneity of an area

• define an entire ecosystem. Without which, the ecosystem would be dramatically different or cease to exist altogether.

• critical for the overall structure and function of an ecosystem, and influence which other types of plants and animals make up that ecosystem.

Tags

NGSS.MS-LS2-4

3.2.1 h - Identify which of the following best describes the role keystone species play in maintaining the structure of an ecological community.

• They have a disproportionately larger effect on their environment and a critical role in maintaining the structure of a specific habitat, even though they may be small in numbers. Their existence helps to; maintain biodiversity, control populations and provide critical resources for a wide range of species within their respective communities and maintains balance of ecological relationships.

• They are species selected for making conservation-related decisions, typically because protecting these species indirectly protects the many other species that make up the ecological community of its habitat. Consequently these species have either large habitat needs or other requirements whose conservation results in many other species being conserved at the ecosystem or landscape level.

• These are species that are very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. They may be at risk due to factors such as habitat loss, poaching and invasive species. Healthy ecosystems depend on plant and animal species as their foundations. When a species becomes, it is a sign that the ecosystem is slowly falling apart. Each species that is lost triggers the loss of other species within its ecosystem.

• This is an organism that helps define an entire ecosystem. Without it, the ecosystem would be dramatically different or cease to exist altogether. They have low functional redundancy. This means that if the species were to disappear from the ecosystem, no other species would be able to fill its ecological niche. The ecosystem would be forced to radically change, allowing new and possibly invasive species to populate the habitat.

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NGSS.MS-LS2-4

NGSS.MS-LS2-5

3.2.1 i - Analyse the given food web to identify the keystone species.

• Dingo

• Southern Cassowary

• Eastern Brown snake

• Rufous Owl

• Lily pilly

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NGSS.MS-LS2-1

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3.2.1 i - Analyse the given food web to identify the keystone species.

• Baleen whale

• Krill

• smaller toothed whales

• fish

• Carnivorous Plankton

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NGSS.MS-LS2-1

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3.2.1 h - Identify which of the following is NOT a role of Keystone Species.

• maintaining biodiversity (through ecological services)

• controls populations (controlling dominant species)

• provides critical resources for a wide range of species

• maintains balance of ecological relationships

• Increases productivity of communities

Tags

NGSS.MS-LS2-2

NGSS.MS-LS2-4

NGSS.MS-LS2-5

3.2.1 h - Identify which of the following is a role of Keystone Species.

• efficient transfer of energy (through ecological services)

• controls populations (controlling dominant species)

• Increases productivity of communities

• Increases biodiversity (through competitive exclusion)

Tags

NGSS.MS-LS2-2

NGSS.MS-LS2-4

NGSS.MS-LS2-5

3.2.1 h - PAST EXAM 2021 SA 1 MC20 - A keystone species is defined as a species that

• is the top predator in an ecosystem.

• is a major producer in an ecosystem.

• has a unique and crucial role in an ecosystem.

• directly influences all species in an ecosystem.

Tags

NGSS.MS-LS2-5