Grade 7 · Science · Unit 4 of 14
People & Ecosystems
Farming, fishing and balance
What your child practises
How agriculture, harvesting and technologies affect ecosystems, such as monoculture, overfishing, invasive species and runoff, and ways to protect and restore balance. Includes reading simple data about an environmental measure.
Alberta Curriculum learning outcome: Unit A: Interactions and Ecosystems · how people and their technologies affect ecosystems
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
What is monoculture?
- Raising many animals in a barn
- Growing a single crop over a large area
- Planting a mix of native flowers
- Fishing for one species only
Show answer
Growing a single crop over a large area
Hint: Mono means one.
Question 2
Overfishing happens when…
- fish are caught only in winter
- fish are returned to the water
- too many fish are born at once
- fish are caught faster than they can reproduce
Show answer
fish are caught faster than they can reproduce
Hint: If the catch is bigger than the new fish being born, the population falls.
Question 3
How can a town best tell whether a pollution-control program is working?
- Check how much money it cost
- Count how many posters were printed
- Compare measurements of the ecosystem before and after the program
- Ask only the people who started it
Show answer
Compare measurements of the ecosystem before and after the program
Hint: Evidence about the ecosystem shows the effect, not the effort.
Question 4
Drip irrigation delivers water slowly to plant roots. What is one environmental benefit?
- It dries out the groundwater faster
- It removes soil from fields
- It adds more fertilizer to rivers
- It uses less water than spraying a whole field
Show answer
It uses less water than spraying a whole field
Hint: Less water is lost to evaporation and runoff.
Question 5
A fishing quota is…
- a way of counting boats
- a type of net
- a limit on how many fish can be caught
- a fee paid by fish
Show answer
a limit on how many fish can be caught
Hint: Limits give fish populations time to recover.
Question 6
Does it harm an ecosystem's balance or help restore it? Sort each action.
Sort into: ⚠️ can harm balance · 🌱 helps restore balance
- 🌳planting native trees along a stream
- 🌉building wildlife crossings over a highway
- 🎣catching fish faster than they can reproduce
- 🅿️draining a wetland for a parking lot
- 🌽growing one crop on the same field every year
- 📏setting a limit on how many fish can be caught
- 🔄rotating crops from year to year
- 🧪letting fertilizer wash into a lake
Show answer
⚠️ can harm balance: catching fish faster than they can reproduce, draining a wetland for a parking lot, growing one crop on the same field every year, letting fertilizer wash into a lake · 🌱 helps restore balance: planting native trees along a stream, building wildlife crossings over a highway, setting a limit on how many fish can be caught, rotating crops from year to year
Hint: Draining wetlands, overfishing and clearing forests without replanting can harm balance. Restoring habitats, setting limits and rotating crops can help.