Decomposition, Soil & Nutrient Availability — Drills · Grade 7 Science
Chapter: Ecosystems, Matter & EnergyWhat these drills covers
By the end of Decomposition, Soil & Nutrient Availability you should be able to:
- I can explain decomposition, soil & nutrient availability.
- 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: soil, nutrient, decomposition, pore space, dry mass.
Problem 1
Which could confound wet-mass decomposition measurements?
- Changed water content
- Correct units alone
- A stated interval alone
- A labeled table alone
Answer and explanation
Changed water content
Water differences affect wet mass independently of dry organic material loss.
Problem 2
Dry material changes from 25 g to 19 g. How much dry mass is lost?
Answer and explanation
6 g
25−19=6 g, without identifying every destination.
Problem 3
Why are spaces in soil relevant?
Answer and explanation
They can hold air and water and affect movement and root conditions, rather than being biologically meaningless empty areas.
Problem 4
Why compare dry masses rather than wet masses alone?
Answer and explanation
Changing water content can alter wet mass without an equivalent change in the organic material being studied.