Pearson Edexcel International GCSE in Biology · 4BI1 · Free · no account needed
Diffusion, Osmosis and Active Transport — exam questions
11 original Incandio exam-style questions on Diffusion, Osmosis and Active Transport, 32 marks, about 32 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 Diffusion, Osmosis and Active Transport — 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
9 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 what is meant by (1–2 marks)
- the definition
- 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
- Describe (2–4 marks)
- developed, linked statements of WHAT happens — no reason required, but detail is Misread as: giving one bare statement where the tariff asked for a developed account
- Give (1–2 marks)
- a short factual answer drawn from recall or from the data
- Use (2–5 marks)
- the supplied data, graph or diagram applied to reach a result — the data is not optional
- Compare (2–4 marks)
- explicit points of similarity or difference, each naming BOTH things
- Design (4–6 marks)
- a workable method: variables, control, measurement, repeats
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 2.15 · 2.16 · 2.17. 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 11 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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A student cut six identical cylinders from the same potato, blotted them dry and weighed each one. She left each cylinder in a different sugar solution for two hours, then blotted and reweighed them.
Table 1 — the percentage change in mass of each potato cylinder after two hours. Sugar concentration / mol dm⁻³ Percentage change in mass / % 0.0 +11.4 0.2 +6.1 0.4 +0.8 0.6 −4.7 0.8 −9.2 1.0 −12.6 (a)
(1)Give
Give one variable the student needed to control in this investigation.
A student cut six identical cylinders from the same potato, blotted them dry and weighed each one. She left each cylinder in a different sugar solution for two hours, then blotted and reweighed them.
Table 1 — the percentage change in mass of each potato cylinder after two hours. Sugar concentration / mol dm⁻³ Percentage change in mass / % 0.0 +11.4 0.2 +6.1 0.4 +0.8 0.6 −4.7 0.8 −9.2 1.0 −12.6 (b)
(2)Use
Use the results in Table 1 to find the sugar concentration inside the potato cells.
A student cut six identical cylinders from the same potato, blotted them dry and weighed each one. She left each cylinder in a different sugar solution for two hours, then blotted and reweighed them.
Table 1 — the percentage change in mass of each potato cylinder after two hours. Sugar concentration / mol dm⁻³ Percentage change in mass / % 0.0 +11.4 0.2 +6.1 0.4 +0.8 0.6 −4.7 0.8 −9.2 1.0 −12.6 (c)
(4)Explain
Explain why the cylinder in the 1.0 mol dm⁻³ solution lost mass.
A student cut six identical cylinders from the same potato, blotted them dry and weighed each one. She left each cylinder in a different sugar solution for two hours, then blotted and reweighed them.
Table 1 — the percentage change in mass of each potato cylinder after two hours. Sugar concentration / mol dm⁻³ Percentage change in mass / % 0.0 +11.4 0.2 +6.1 0.4 +0.8 0.6 −4.7 0.8 −9.2 1.0 −12.6 (Total for Question 1 = 7 marks)
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(1)Which
Which process moves substances against a concentration gradient?
Process A diffusion B osmosis C active transport D evaporation (Total for Question 2 = 1 mark)
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(2)State what is meant by
State what is meant by osmosis.
(Total for Question 3 = 2 marks)
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(3)Explain
A root hair cell takes up nitrate ions from the soil even though the soil contains fewer nitrate ions than the cell does. Explain how this is possible.
(Total for Question 4 = 3 marks)
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(3)Explain
The lining of the small intestine is folded into villi, and each villus is covered in microvilli. Explain how this affects the rate at which glucose is absorbed.
(Total for Question 5 = 3 marks)
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(3)Suggest
A single-celled organism 0.1 mm across can supply all its cells' needs by diffusion alone. A whale cannot. Suggest why.
(Total for Question 6 = 3 marks)
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(4)Describe
Describe how a student could use potato cylinders to find the sugar concentration inside potato cells.
(Total for Question 7 = 4 marks)
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(3)Compare
Compare diffusion and active transport.
(Total for Question 8 = 3 marks)
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(6)Design
Design an experiment using cubes of agar containing an indicator to show how surface area to volume ratio affects the rate at which a substance reaches the centre of a block.
(Total for Question 9 = 6 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 — 11 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain Diffusion, Osmosis and Active Transport to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Henri Dutrochet over three rounds, marked against descriptors you can read first.
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Back to the lesson
- Diffusion, Osmosis and Active Transport — The three ways anything gets into or out of a cell — which need energy, which do not, and what makes each one fast or slow.
- All of Incandio Biology · Incandio Exam Practice