Human Activities, Habitat & Environmental Evidence — Practice · Grade 7 Science

Chapter: Ecological Evidence & Environmental Design

What this practice covers

By the end of Human Activities, Habitat & Environmental Evidence you should be able to:

8 questions, written answer, multiple choice and numeric, each with a worked explanation.

Vocabulary used: habitat fragmentation, infiltration, impervious surface, outcome, tradeoff.

Problem 1

Why does a mapped barrier not prove an exact population loss?
Answer and explanation

Actual effects depend on movement, species needs, alternative routes, and observations not given by the line alone.

Problem 2

Does clearer water prove every contaminant is absent?
Answer and explanation

No. Some dissolved substances or organisms are not revealed by clarity alone.

Problem 3

Why distinguish planted area from surviving cover?
Answer and explanation

Planting is an action; later survival and cover are outcomes requiring observations.

Problem 4

Can two different recommendations both be well supported?
Answer and explanation

Yes, if they use evidence accurately, state criteria and constraints, and explain tradeoffs and uncertainty.

Problem 5

Illustrative matched-rain model: Area A sends 18 L to surface runoff and Area B 10 L after a vegetation treatment. Starting conditions are stated comparable, but only one trial is supplied. Calculate the difference, explain a plausible pathway, and qualify a universal water-quality claim.
Answer and explanation

B has 8 L less recorded runoff in this illustrative trial. Vegetation-associated retention or infiltration could contribute under the stated comparison. The record does not establish all causal details, repeated performance, or absence of contaminants. More matched trials and separate water-quality measures are needed for stronger claims.

Difference: 18−10=8 L.

Connect vegetation and soil with possible infiltration or retention.

Separate runoff amount from all water-quality properties and identify the single-trial limit.

Response criteria

  • Explain the relevant biological process accurately.
  • Use the supplied evidence and show calculation steps with units where needed.
  • Connect a labeled model or mechanism with the claim.
  • State an assumption, evidence limitation, or useful next observation.

Problem 6

A project reports 100 planted seedlings. What should be measured before claiming habitat function was restored?
Answer and explanation

Survival, developing cover, relevant species use, and defined ecosystem functions over time would test outcomes beyond the initial planting count.

Response criteria

  • Explain the relevant biological process accurately.
  • Use the supplied evidence and show calculation steps with units where needed.
  • Connect a labeled model or mechanism with the claim.
  • State an assumption, evidence limitation, or useful next observation.

Problem 7

Which is an outcome rather than only an activity count?
  1. Number planted on day one
  2. Surviving cover after a defined interval
  3. Number of notices printed
  4. Project name
Answer and explanation

Surviving cover after a defined interval

Surviving cover measures a later result, while initial planting is an action count.

Problem 8

A model receives 30 L rain input and has 9 L runoff. What percent becomes recorded runoff?
Answer and explanation

30 %

9/30×100=30% under the stated boundary and interval.

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