Cambridge IGCSE Biology 0610: Transport in animals – 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 topic 9, Transport in animals, of the Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028: sections 9.1 Circulatory systems, 9.2 Heart, 9.3 Blood vessels and 9.4 Blood. Questions and parts marked (Extended) test Supplement content, which only Extended candidates (Papers 2 and 4) need. Everything else is Core. Calculators may be used throughout.

Before you start, read the transport in animals study guide or the revision notes. Course pages: Cambridge IGCSE Biology hub and printable checklist.

Questions

1. State what is meant by a circulatory system. [2]

2. A diagram of the human heart shows labelled structures.

(a) Name the chamber that pumps blood into the aorta. [1] (b) Name the blood vessel that brings deoxygenated blood from the body to the heart. [1] (c) Name the structure that separates the left side of the heart from the right side. [1]

3.

(a) Describe two differences in structure between an artery and a vein. [2] (b) State the function of capillaries. [1]

4. An ECG trace from a patient shows one peak every 0.60 seconds.

(a) Calculate the patient’s heart rate in beats per minute. Show your working. [2] (b) State two other ways the activity of the heart can be monitored. [2]

5. (Extended)

(a) Describe the single circulation of a fish. [2] (b) Explain three advantages of the double circulation of a mammal. [3]

6. A blood smear is viewed under a microscope.

(a) State the function of platelets. [1] (b) Name two substances, other than blood cells, that are transported in plasma. [2] (c) (Extended) Cell P has a large round nucleus that fills most of the cell. Cell Q has a lobed nucleus and more cytoplasm. Identify cells P and Q and state the function of each. [3]

7. (Extended) Explain the relative thickness of:

(a) the muscle walls of the left and right ventricles [2] (b) the muscle walls of the atria compared with those of the ventricles. [2]

8. (Extended) Describe the functioning of the heart during one heartbeat, in terms of the contraction of the atria and ventricles and the action of the valves. [5]

9. A student counts his pulse for 15 seconds at rest and gets 18 beats. He then skips for two minutes and immediately counts 31 beats in 15 seconds.

(a) Calculate his resting heart rate in beats per minute. [1] (b) Calculate the percentage increase in his heart rate after skipping. Give your answer to the nearest whole number. [2] (c) Suggest two variables he should keep the same if he repeats the investigation on another day. [2] (d) (Extended) Explain why his heart rate increased during skipping. [3]

10.

(a) Describe coronary heart disease. [2] (b) State two risk factors for coronary heart disease that a person cannot change. [2] (c) Discuss the roles of diet and exercise in reducing the risk of coronary heart disease. [4]

11. (Extended)

(a) Explain how the structure of an artery is related to the pressure of the blood it carries. [2] (b) Explain how the structure of a vein is related to the pressure of the blood it carries. [2] (c) Explain how the structure of capillaries is related to their function. [2] (d) Name the blood vessel that carries blood from the gut to the liver, and the vessels that carry blood away from the liver. [2]

12.

(a) State two roles of blood clotting. [2] (b) (Extended) Describe the process of clotting. [2]

Answers

1. A system of blood vessels with a pump (the heart) [1] and valves that ensure blood flows in one direction only [1]. Examiner insight: The two marks are for “vessels + pump” and “valves for one-way flow”; leaving out the valves limits you to one mark.

2. (a) Left ventricle [1]. (b) Vena cava [1]. (c) Septum [1]. Examiner insight: Naming marks need the correct term spelt recognisably; “ventricle” without “left” or “vein” instead of “vena cava” is not specific enough to score.

3. (a) Arteries have a thicker (more muscular) wall than veins [1]; arteries have a narrower lumen / veins have valves [1]. (b) Exchange of substances between the blood and the body cells [1]. Examiner insight: Each difference must be a comparison (“thicker than”), not a one-sided statement such as “arteries have thick walls” with nothing about veins.

4. (a) 60 ÷ 0.60 [1] = 100 beats per minute [1]. (b) Counting the pulse rate [1]; listening to the sounds of the valves closing (with a stethoscope) [1]. Examiner insight: A correct final answer usually earns both marks, but the working mark is your safety net if you slip on the arithmetic, so write the division down.

5. (a) Blood flows from the heart to the gills, then to the body, then back to the heart [1]; it passes through the heart once in each complete circuit [1]. (b) Blood returns to the heart from the lungs and is pumped again, so it reaches the body at high pressure / flows faster [1]; blood can go to the lungs at lower pressure, avoiding damage to lung capillaries [1]; oxygenated and deoxygenated blood are kept separate, so blood to the body carries more oxygen [1]. Examiner insight: “Explain” needs the reason attached to each advantage; “higher pressure” alone, without the faster delivery of blood to the body, is often not enough for the mark.

6. (a) Clotting (of blood) [1]. (b) Any two of: ions, nutrients (e.g. glucose), urea, hormones, carbon dioxide [1] [1]. (c) P is a lymphocyte, which produces antibodies [1]; Q is a phagocyte [1], which engulfs pathogens by phagocytosis [1]. Examiner insight: In (b), “blood cells” is excluded by the question and “oxygen” is wrong, because oxygen is carried by red blood cells.

7. (a) The left ventricle wall is thicker because it pumps blood all round the body [1] at a higher pressure; the right ventricle pumps blood only to the lungs, at lower pressure [1]. (b) The atria have thinner walls because they only pump blood into the ventricles [1]; the ventricles pump blood out of the heart into the arteries, over a greater distance / at higher pressure [1]. Examiner insight: Answers that say the left ventricle pumps “more blood” do not score; the credited idea is pressure and distance, not volume.

8. The atria contract, pushing blood into the ventricles [1]. The ventricles then contract [1], which closes the atrioventricular valves so blood cannot flow back into the atria [1]. The semilunar valves open and blood is forced into the aorta and pulmonary artery [1]. When the ventricles relax, the semilunar valves close, preventing backflow from the arteries [1]. Examiner insight: Sequence matters: each valve mark needs the right valve linked to the right event, so “the valves close” without saying which ones earns little.

9. (a) 18 × 4 = 72 beats per minute [1]. (b) After skipping: 31 × 4 = 124 beats per minute; (124 − 72) ÷ 72 × 100 [1] = 72.2% = 72% [1]. (c) Any two of: duration of skipping; speed / intensity of skipping; time between stopping and counting; length of counting period [1] [1]. (d) Muscles contract more, so their cells respire faster [1]; they need more oxygen and glucose delivered [1] and more carbon dioxide removed, so the heart pumps blood faster [1]. Examiner insight: In (b), dividing by 124 instead of 72 gives 42% and loses the method mark; always divide by the original value. Error carried forward is usually allowed from a wrong answer in (a).

10. (a) The coronary arteries become blocked (e.g. by fatty deposits) [1], so the heart muscle receives less oxygen and glucose and cannot respire / may die [1]. (b) Any two of: genetic predisposition, age, sex [1] [1]. (c) A diet low in saturated fat / cholesterol reduces fatty deposits in arteries [1]; eating less salt helps keep blood pressure down [1]; regular exercise strengthens the heart / helps control body mass / lowers blood pressure [1]; but neither diet nor exercise removes risks such as age, sex or genetic predisposition [1]. Examiner insight: A “discuss” answer needs both diet and exercise covered; a list of risk factors without saying how diet or exercise reduces the risk earns very little.

11. (a) Arteries carry blood at high pressure, so they have a thick, muscular wall that withstands the pressure [1]; elastic tissue stretches and recoils to keep blood flowing / even out the pressure [1]. (b) Veins carry blood at low pressure, so a thin wall is enough and the wide lumen reduces resistance [1]; valves prevent backflow [1]. (c) The wall is one cell thick, giving a short diffusion distance [1]; many capillaries give a large surface area / bring blood close to every cell [1]. (d) Hepatic portal vein [1]; hepatic veins [1]. Examiner insight: Each structure mark needs a link to pressure or function; describing the vessel alone, as you would at Core, does not answer an “explain” question.

12. (a) Prevents blood loss [1]; prevents entry of pathogens [1]. (b) Soluble fibrinogen is converted to insoluble fibrin [1]; fibrin forms a mesh that traps blood cells to form a clot [1]. Examiner insight: Reversing the conversion (“fibrin to fibrinogen”) loses the mark; the syllabus wording is fibrinogen to fibrin.

Where marks are usually lost

• Defining an artery by its oxygen content instead of the direction of flow away from the heart.
• Naming “the valves” without saying atrioventricular or semilunar in an Extended answer.
• Comparing ventricles by volume pumped instead of pressure produced and distance travelled.
• Giving one-sided vessel descriptions (“veins have valves”) when the question asks for differences.
• Forgetting to convert a 15-second pulse count to beats per minute.
• Dividing a percentage change by the final value instead of the starting value.
• Listing CHD risk factors when the question asks how diet and exercise reduce risk.
• Saying plasma carries oxygen, or that phagocytes produce antibodies.

Next steps

• Recap with the transport in animals revision notes.
• Re-read any weak section in the study guide.
• Move on to topic 10 with the diseases and immunity practice questions.
• Take the 0610 Core diagnostic or 0610 Extended diagnostic.
• Browse the Cambridge IGCSE Biology hub and tick off the printable checklist.
• Book a free trial class.

Official syllabus

Cambridge IGCSE Biology 0610 syllabus for examination in 2026, 2027 and 2028 (Version 3), section 9 Transport in animals. Published by Cambridge University Press & Assessment.