Edexcel International GCSE Biology 4BI1: Transport – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions cover sub-topic (h) Transport (points 2.51–2.69 of Topic 2) of the Pearson Edexcel International GCSE Biology (4BI1) specification, Issue 3. The course is untiered and a calculator may be used on both papers. Questions 5, 6, 7 and 9 test bold B statements and are labelled “Paper 2 only”.

Learn the content first in the Transport study guide and the Transport revision notes. For questions on cells and enzymes, use the cell structure practice questions. The course hub is Edexcel IGCSE Biology and the printable checklist lists every point.

Questions

1. A student models organisms as cubes. Cube A has sides of 1 mm. Cube B has sides of 5 mm.

(a) Calculate the surface area to volume ratio of each cube. [2] (b) Use your answers to explain why a large multicellular organism needs a transport system but a unicellular organism does not. [3]

2. Give two differences between transport in xylem and transport in phloem. [2]

3. Name the substance carried in the plasma from:

(a) the liver to the kidneys [1] (b) the small intestine to muscle cells [1] (c) respiring muscle cells to the lungs. [1]

4. Explain how the structure of a red blood cell makes it suited to transporting oxygen. [4]

5. (Paper 2 only) A student uses a potometer with a capillary tube of radius 0.4 mm. In still air the bubble moves 18 mm in 3 minutes. With a fan blowing on the shoot, the bubble moves 45 mm in 3 minutes.

(a) Calculate the volume of water taken up per minute in still air. Give your answer to 3 significant figures. [2] (b) Calculate the percentage increase in the rate of water uptake when the fan is switched on. [2] (c) Explain why the fan increases the rate of transpiration. [2] (d) State two variables the student should keep constant. [2]

6. (Paper 2 only) A leafy shoot stands in a flask of water with a layer of oil on the surface. The flask and shoot have a mass of 152.60 g at the start and 149.72 g after 8 hours.

(a) Calculate the mean rate of mass loss in g per hour. [2] (b) Explain why there is a layer of oil on the water. [1] (c) The experiment is repeated in more humid air, with all other conditions the same. Predict and explain the effect on the rate of mass loss. [2]

7. (Paper 2 only) Explain how water from the soil enters a root hair cell. [3]

8. Describe how phagocytes and lymphocytes protect the body against a pathogen. [4]

9. (Paper 2 only) A person receives a vaccine against a virus. Months later, the same virus enters their body. The peak antibody concentration after the vaccine was 16 arbitrary units; after the later infection it was 240 arbitrary units.

(a) Calculate how many times greater the second peak is than the first. [1] (b) Explain why the person does not become ill after the later infection. [3] (c) Explain how platelets reduce the chance of infection when the skin is cut. [3]

10. A student’s resting heart rate is 76 beats per minute. During a run it rises to 140 beats per minute.

(a) Calculate the percentage increase in heart rate. Give your answer to 1 decimal place. [2] (b) Explain why heart rate increases during exercise. [4] (c) Name the hormone, and the gland that secretes it, that increases heart rate when a person is frightened. [2]

11. This question is about the heart.

(a) Describe the path taken by blood from the vena cava to the aorta. [4] (b) Explain why the wall of the left ventricle is thicker than the wall of the right ventricle. [2] (c) State the function of the valves in the heart. [1] (d) A coronary artery becomes narrowed. Explain how this could lead to a heart attack, and give two lifestyle factors that increase the risk. [4]

12. This question is about blood vessels and the circulation.

(a) Compare the structure of an artery with the structure of a vein. [3] (b) Explain how the structure of a capillary suits its function. [2] (c) Name the blood vessel that carries blood to the kidneys, and the vessel that carries blood from the gut to the liver. [2]

Answers

1. (a) A: SA = 6 mm², V = 1 mm³, ratio 6 : 1 [1]; B: SA = 150 mm², V = 125 mm³, ratio 1.2 : 1 [1] (b) The larger organism has a smaller surface area to volume ratio [1]; its inner cells are a long way from the surface, so diffusion would be too slow to supply them [1]; a unicellular organism has a large ratio and short diffusion distance, so diffusion across its membrane is enough [1] Examiner insight: Each ratio needs both the area and the volume to be right; an answer that only says “B is bigger” without linking size to diffusion distance or rate does not get the explanation marks.

2. Xylem carries water and mineral ions; phloem carries sucrose and amino acids [1]; xylem flow is upwards only, while phloem moves substances up and down the plant [1] Examiner insight: A difference must state both sides; “phloem carries sugar” alone does not score unless you also say what xylem carries.

3. (a) Urea [1] (b) Glucose (or amino acids / digested food) [1] (c) Carbon dioxide [1] Examiner insight: In (c), “oxygen” is a common wrong answer: oxygen travels in red blood cells and moves towards muscles, not away from them.

4. Biconcave shape [1]; gives a large surface area to volume ratio for fast diffusion of oxygen [1]; no nucleus, so more space for haemoglobin [1]; haemoglobin combines with oxygen to form oxyhaemoglobin [1] Examiner insight: Features and explanations are marked separately, so a list of three features with no reasons scores half the marks at most.

5. (a) π × 0.4² × 18 = 9.048 mm³ in 3 minutes [1]; 9.048 ÷ 3 = 3.02 mm³ per minute [1] (b) (45 − 18) ÷ 18 × 100 [1] = 150% [1] (c) Moving air carries water vapour away from the leaf surface, keeping the water vapour concentration gradient steep [1]; so water vapour diffuses out of the stomata faster [1] (d) Any two: temperature [1]; light intensity [1]; humidity; the same shoot Examiner insight: In (b) the distances can be used directly because the tube radius is the same; dividing by the new value (45) instead of the original (18) loses the answer mark.

6. (a) 152.60 − 149.72 = 2.88 g lost [1]; 2.88 ÷ 8 = 0.36 g per hour [1] (b) To stop water evaporating from the water surface, so all the loss is from the shoot [1] (c) The rate decreases [1]; the more humid air means the water vapour concentration gradient between leaf and air is smaller and less water vapour diffuses out [1] Examiner insight: “Predict and explain” carries a mark for the direction and a separate one for the reason; a reason without a stated prediction loses the first mark.

7. Cell sap in the root hair cell is more concentrated than the soil water [1]; water moves into the cell by osmosis [1]; across the partially permeable cell membrane, from a dilute to a more concentrated solution [1] Examiner insight: Saying water enters by “diffusion” or “active transport” is not credited; the mark needs the word osmosis.

8. Phagocytes engulf (ingest) pathogens [1]; and digest them [1]; lymphocytes release antibodies [1]; which are specific to the pathogen’s antigens [1] Examiner insight: Two separate points are needed for each cell type; “white blood cells kill pathogens” without naming what each type does scores nothing.

9. (a) 240 ÷ 16 = 15 times [1] (b) The vaccine caused lymphocytes to produce memory cells [1]; on infection, memory cells make antibodies sooner and faster [1]; and in greater quantity, so the virus is destroyed before symptoms develop [1] (c) Platelets trigger conversion of soluble fibrinogen to insoluble fibrin [1]; fibrin threads form a mesh that traps red blood cells to form a clot [1]; the clot seals the wound so micro-organisms cannot enter [1] Examiner insight: In (b), saying the vaccine “contains antibodies” or “kills the virus” contradicts the mechanism and loses the first mark.

10. (a) (140 − 76) ÷ 76 × 100 [1] = 84.2% [1] (b) Muscles respire faster and need more oxygen and glucose [1]; more carbon dioxide is produced and is detected by the brain [1]; nerve impulses make the heart beat faster [1]; so more blood reaches the muscles, delivering oxygen and glucose and removing carbon dioxide faster [1] (c) Adrenaline [1]; adrenal gland [1] Examiner insight: “The heart beats faster to get more oxygen” is too vague for full marks; say that oxygen is needed for aerobic respiration in the muscles.

11. (a) Vena cava → right atrium → right ventricle [1]; → pulmonary artery → lungs [1]; → pulmonary vein → left atrium [1]; → left ventricle → aorta [1] (b) The left ventricle pumps blood all round the body [1]; so it must generate a higher pressure than the right ventricle, which pumps only to the lungs [1] (c) To prevent the backflow of blood [1] (d) Fatty deposits narrow the coronary artery, so less blood and oxygen reach the heart muscle [1]; heart muscle cannot respire aerobically and cells die, causing a heart attack [1]; any two of: smoking, diet high in saturated fat or salt, lack of exercise [1] [1] Examiner insight: In (a), one wrong or missing structure loses the mark for that stage of the route, so write the full chain in order with no gaps.

12. (a) Artery has a thicker wall than a vein [1]; artery has more muscle and elastic tissue [1]; vein has a wider lumen and valves [1] (b) Wall is one cell thick, giving a short diffusion distance [1]; so substances such as oxygen and glucose diffuse quickly between blood and tissue cells [1] (c) Renal artery [1]; hepatic portal vein [1] Examiner insight: “Compare” needs a point about both vessels in each comparison; writing “arteries are thick” with no reference to veins earns limited credit.

Where marks are usually lost

• Calculating surface area to volume ratio with the area of only one face.
• Defining transpiration without the word evaporation, or saying water (not water vapour) leaves through the stomata.
• Explaining a potometer result without referring to the concentration gradient of water vapour.
• Saying a potometer measures transpiration exactly: it measures water uptake.
• Giving “food” or “nutrients” for what xylem carries.
• Mixing up phagocytes and lymphocytes, or saying antibodies “eat” pathogens.
• Saying vaccines contain antibodies.
• Writing “the heart pumps faster to get more energy” with no link to oxygen or respiration.
• Naming the hepatic vein instead of the hepatic portal vein for blood from the gut.
• Dividing by the new value instead of the original value in percentage change calculations.

Next steps

• Recap with the Transport revision notes.
• Relearn anything you dropped marks on in the Transport study guide.
• Course hub: Edexcel IGCSE Biology.
• Tick off points on the printable checklist.
• Try all free 10-minute diagnostics.
• Book a free trial class.

Official syllabus

Pearson Edexcel International GCSE in Biology (4BI1), Specification, Issue 3, September 2024, Pearson Education Limited: Topic 2, sub-topic (h) Transport, points 2.51–2.69.