Sampling Ecosystems & Comparing Evidence — Drills · Grade 7 Science
Chapter: Ecological Evidence & Environmental DesignWhat these drills covers
By the end of Sampling Ecosystems & Comparing Evidence you should be able to:
- I can explain sampling ecosystems & comparing evidence.
- 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: sample, quadrat, transect, density, sampling bias.
Problem 1
Which choice reduces the stated location-selection problem?
- Only sample favorite patches
- Use a predefined representative location plan
- Delete low counts
- Change plot size secretly
Answer and explanation
Use a predefined representative location plan
A planned sampling method helps address selection bias, though other limits remain.
Problem 2
A survey detects 18 plants across 6 m². Find density.
Answer and explanation
3 plants/m²
18/6=3 plants/m² under the stated detection method.
Problem 3
Why specify whether sightings or individuals are counted?
Answer and explanation
Repeated sightings can involve one individual; the quantities answer different questions.
Problem 4
Why can equal plot counts differ in density?
Answer and explanation
Plot areas can differ; count per area accounts for that boundary.