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, Oregon's estuaries and Pacific Northwest forests as examples.
Oregon State 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?
- A sudden freeze
- A volcanic eruption
- A wildfire
- Disease spreading in a crowded population
Disease spreading in a crowded population
Hint: Gets worse as crowding increases.
Question 2
A limiting factor is something that…
- has no effect
- makes populations grow forever
- keeps a population from growing larger
- only affects plants
keeps a population from growing larger
Hint: Food, water, space.
Question 3
A stable ecosystem…
- cannot recover
- never changes at all
- returns to similar conditions after small disturbances
- has only one species
returns to similar conditions after small disturbances
Hint: Resilience.
Question 4
About what percent of energy passes from one trophic level to the next?
- 50%
- 10%
- 90%
- 100%
10%
Hint: Most is lost as heat.
Question 5
Ocean acidification harms…
- shellfish building shells
- volcanoes
- sunlight
- mountains
shellfish building shells
Hint: Acid dissolves shell material.
Question 6
If producers capture 10,000 kJ, about how much reaches the secondary consumers?
- 10 kJ
- 5000 kJ
- 1000 kJ
- 100 kJ
100 kJ
Hint: 10% then 10% again.