Interactions & Ecosystem Change — Drills · Grade 7 Science
Chapter: Ecological Evidence & Environmental DesignWhat these drills covers
By the end of Interactions & Ecosystem Change you should be able to:
- I can explain interactions & ecosystem change.
- I can use evidence, a model, and stated assumptions to support a biological explanation.
4 questions, multiple choice, numeric and written answer, each with a worked explanation.
Vocabulary used: competition, predation, mutualism, parasitism, disturbance.
Problem 1
Which identifies competition most directly?
- Shared use of a limiting resource
- Any two different colors
- Every insect landing
- Any pair of graph axes
Answer and explanation
Shared use of a limiting resource
Competition concerns limiting-resource overlap and its effects.
Problem 2
Plant cover changes from 70% to 45%. Find the decrease in percentage points.
Answer and explanation
25 percentage points
70−45=25 percentage points, distinct from a percent decrease relative to 70.
Problem 3
Does sharing a habitat alone prove competition?
Answer and explanation
No. Resource overlap and limitation, or effects on performance, need evidence.
Problem 4
What observation could strengthen a predation explanation?
Answer and explanation
Relevant feeding evidence and repeated population records, considered with alternative resources and conditions, can strengthen it.