Biology SL
Collaborative Water-Quality Planning
- 1.
For a hypothetical team project on a river, biology students propose counting invertebrates, chemistry students propose nitrate tests and physics students propose measuring flow. Design a shared sampling plan that allows the three datasets to be interpreted together. Identify four essential coordination decisions.
[4 marks] · no calculator - 2.
Two hypothetical team members report dissolved oxygen at the same site as 8.0 mg dm^-3 and 80% saturation. One suggests averaging the numbers to get 44. Explain why that is invalid and propose three checks before combining or comparing the results.
[4 marks] · no calculator - 3.
A hypothetical team's two downstream samples show fewer invertebrate species than two upstream samples. The team proposes publicly blaming a named farm for pollution. Evaluate the proposed claim and give two scientifically and ethically defensible next steps.
[4 marks] · no calculator - 4.
For a hypothetical joint river project, a biology team counts 24 individuals of one invertebrate taxon in a total sampled bed area of 0.30 m^2 upstream and 30 individuals in 0.60 m^2 downstream. A chemistry teammate concludes the higher downstream count indicates better conditions there. Calculate densities and evaluate that conclusion. Assume equal capture efficiency solely for the calculation. Propose a shared next sampling decision that also tests a limitation of that assumption.
[4 marks] - 5.
A hypothetical biology-physics-chemistry team proposes moving the same wet net, flow meter and sample bottles between two ponds. One pond may contain an invasive aquatic organism. Design four linked decisions that allow all three disciplines to obtain comparable evidence while reducing organism transfer and documenting the plan. No organism presence is confirmed and no sampling is authorised by this exercise.
[4 marks] · no calculator