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9th grade · Science · Unit 11 of 11

Ecosystem Dynamics

Carrying capacity, energy pyramids and human impacts.

What your child practices

Practices carrying capacity, energy flow and the 10% rule, how ecosystems respond to disturbance, and evaluating solutions to human impacts, using California's chaparral, kelp forests and salmon rivers as examples.

California Content Standards learning standard: HS-LS2-1; HS-LS2-4; HS-LS2-6; HS-LS2-7 · carrying capacity, energy flow, ecosystem stability and reducing human impacts on biodiversity

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Chaparral shrubs sprouting again after a wildfire are an example of…

    • extinction
    • erosion only
    • photosynthesis only
    • succession

  2. Question 2

    Removing wolves from an ecosystem led to more elk and fewer young trees. This shows…

    • wolves eat trees
    • elk are producers
    • trees eat elk
    • top predators shape whole ecosystems

  3. Question 3

    Which is a density-dependent limiting factor?

    • A sudden freeze
    • A wildfire
    • Disease spreading in a crowded population
    • A volcanic eruption

  4. Question 4

    Which data best show whether a stream restoration helped?

    • One photo of the stream
    • Counts of returning salmon over several years
    • The number of visitors
    • The color of the water once

  5. Question 5

    When sea otters disappear, sea urchins can wipe out kelp. This shows…

    • that kelp needs no animals
    • that urchins are producers
    • that otters eat kelp
    • how one species can keep an ecosystem stable

  6. Question 6

    Which is a density-independent limiting factor?

    • Competition for food
    • A hurricane
    • Disease
    • Predation

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