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 salmon, Puget Sound and Pacific Northwest forests as examples.
Washington State Learning 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.
Question 1
Which is a density-dependent limiting factor?
- Disease spreading in a crowded population
- A volcanic eruption
- A sudden freeze
- A wildfire
Disease spreading in a crowded population
Hint: Gets worse as crowding increases.
Question 2
Which is a density-independent limiting factor?
- Disease
- Predation
- Competition for food
- A hurricane
A hurricane
Hint: Affects everyone regardless of numbers.
Question 3
Primary succession begins on…
- a lawn
- a farm field
- a burned forest with soil
- bare rock with no soil
bare rock with no soil
Hint: Like new lava flows.
Question 4
A limiting factor is something that…
- keeps a population from growing larger
- makes populations grow forever
- has no effect
- only affects plants
keeps a population from growing larger
Hint: Food, water, space.
Question 5
Ocean acidification harms…
- mountains
- volcanoes
- sunlight
- shellfish building shells
shellfish building shells
Hint: Acid dissolves shell material.
Question 6
Hatcheries add salmon, but wild salmon still decline. One reason is…
- rivers are too clean
- salmon don't eat
- hatcheries remove water
- habitat loss limits survival
habitat loss limits survival
Hint: Habitat is a limiting factor.