Pearson Edexcel International GCSE in Biology · 4BI1 · Free · no account needed
Water Pollution and Eutrophication — exam questions
9 original Incandio exam-style questions on Water Pollution and Eutrophication, 18 marks, about 18 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Water Pollution and Eutrophication — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
5 command words run through this set, and on Pearson Edexcel International GCSE Biology each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- Which (1 mark)
- one option chosen from the set given
- State (1 mark)
- one precise fact, no justification
- Give (1–2 marks)
- a short factual answer drawn from recall or from the data
- Explain (2–4 marks)
- a causal chain — WHY it happens, each link a separate marking point Misread as: describing what happens without giving the reason it happens
- Suggest (1–3 marks)
- a plausible answer applying taught biology to a situation not taught
Assessed on Paper 1 (4BI1/1B) and Paper 2 (4BI1/2B), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Biology (4BI1) — statements 4.17 · 4.16. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 9 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
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Table 1 — measurements taken in a river at four points. Point 1 is upstream of a sewage outfall; points 2, 3 and 4 are 100 m, 800 m and 4 km downstream of it. Point Dissolved oxygen / mg per dm³ Nitrate / mg per dm³ Number of fish species 1 (upstream) 9.8 2 11 2 (100 m) 3.1 27 1 3 (800 m) 5.4 24 3 4 (4 km) 9.1 8 9 (a)
(1)Give
Give the point in Table 1 at which the dissolved oxygen concentration is lowest.
Table 1 — measurements taken in a river at four points. Point 1 is upstream of a sewage outfall; points 2, 3 and 4 are 100 m, 800 m and 4 km downstream of it. Point Dissolved oxygen / mg per dm³ Nitrate / mg per dm³ Number of fish species 1 (upstream) 9.8 2 11 2 (100 m) 3.1 27 1 3 (800 m) 5.4 24 3 4 (4 km) 9.1 8 9 (b)
(3)Explain
Explain the relationship between the oxygen concentration and the number of fish species in Table 1.
Table 1 — measurements taken in a river at four points. Point 1 is upstream of a sewage outfall; points 2, 3 and 4 are 100 m, 800 m and 4 km downstream of it. Point Dissolved oxygen / mg per dm³ Nitrate / mg per dm³ Number of fish species 1 (upstream) 9.8 2 11 2 (100 m) 3.1 27 1 3 (800 m) 5.4 24 3 4 (4 km) 9.1 8 9 (c)
(2)Suggest
Suggest why the nitrate concentration at point 4 is still four times the upstream value although the fish have returned.
Table 1 — measurements taken in a river at four points. Point 1 is upstream of a sewage outfall; points 2, 3 and 4 are 100 m, 800 m and 4 km downstream of it. Point Dissolved oxygen / mg per dm³ Nitrate / mg per dm³ Number of fish species 1 (upstream) 9.8 2 11 2 (100 m) 3.1 27 1 3 (800 m) 5.4 24 3 4 (4 km) 9.1 8 9 (Total for Question 1 = 6 marks)
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(1)Which
Which organisms use up the oxygen during eutrophication?
Organisms A the algae B the fish C decomposing bacteria D the water plants (Total for Question 2 = 1 mark)
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(1)State
State where the extra nitrate that causes eutrophication usually comes from.
(Total for Question 3 = 1 mark)
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(1)Give
Give one consequence for humans of sewage entering a river used for drinking water.
(Total for Question 4 = 1 mark)
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(4)Explain
Explain how fertiliser leaching into a lake can lead to the death of the fish in it.
(Total for Question 5 = 4 marks)
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(2)Suggest
Suggest two things a farmer could do to reduce the amount of nitrate leaching from their fields into a nearby stream.
(Total for Question 6 = 2 marks)
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(3)Explain
Explain why a river recovers on its own some distance downstream of a sewage outfall.
(Total for Question 7 = 3 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 9 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Water Pollution and Eutrophication to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Florence Nightingale over three rounds, marked against descriptors you can read first.
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Back to the lesson
- Water Pollution and Eutrophication — Two things that should be harmless — treated sewage and plant fertiliser — and the same chain of events by which both empty a river of fish.
- All of Incandio Biology · Incandio Exam Practice