This set covers five skills: tracing the double circulation, explaining valves with pressure, comparing vessels, linking blood components to roles, and interpreting exercise data. Work through the questions in order, since they go from easier to harder.
Write a full answer for each one before you open the working. All data are invented for practice.
Questions
Q1. Name the chamber that receives blood from the lungs, and the vessel that brings it.
Show answer
The blood returns through the pulmonary vein into the left atrium. It is oxygenated, because it has just passed through the lung capillaries.
Q2. Put these in the order a blood cell passes through them, starting at the vena cava: left ventricle, right atrium, aorta, pulmonary artery, left atrium, right ventricle, pulmonary vein.
Show answer
Vena cava, right atrium, right ventricle, pulmonary artery, lungs, pulmonary vein, left atrium, left ventricle, aorta. The lungs sit between the pulmonary artery and pulmonary vein.
Q3. State what a vein and an artery have in common about the direction of blood flow, and say how they differ.
Show answer
Neither is defined by oxygen content. An artery carries blood away from the heart and a vein carries blood towards the heart. The pulmonary artery carries deoxygenated blood and the pulmonary vein carries oxygenated blood, so the direction rule is the reliable one.
Q4. The pressure in the left ventricle is 16 units and the pressure in the aorta is 11 units. Is the semilunar valve open or shut? Give the reason.
Show answer
It is open. The pressure behind the valve (ventricle, 16) is higher than in front (aorta, 11), so blood pushes the valve open and flows into the aorta.
Q5. Later the ventricle relaxes and its pressure falls to 3 units while the aorta is at 9 units. What does the valve do, and why does this matter?
Show answer
The valve shuts, because the pressure in front (aorta, 9) is now higher than behind (ventricle, 3). This stops blood flowing back into the ventricle, so flow stays one way.
Q6. Give three differences between the structure of an artery and a vein.
Show answer
The artery wall is thicker, with more muscle and elastic fibres. The artery lumen is narrower. The vein has valves, while most arteries do not. Linking to function: the thick wall withstands high pressure, and valves stop backflow at low pressure.
Q7. Explain how the structure of a capillary helps exchange between blood and a muscle cell.
Show answer
The wall is one cell thick, which gives a very short diffusion distance. Oxygen and glucose diffuse out into the muscle and carbon dioxide diffuses in. The capillary is also very narrow and close to the cells, so blood moves slowly past them.
Q8. Match each to its job: red blood cell, platelet, phagocyte, plasma. Jobs: clotting, carrying dissolved glucose and urea, carrying oxygen, engulfing pathogens.
Show answer
Red blood cell: carrying oxygen (haemoglobin). Platelet: clotting. Phagocyte: engulfing pathogens. Plasma: carrying dissolved glucose and urea.
Q9. An invented pulse count is 18 beats in 15 seconds at rest, and 30 beats in 15 seconds after exercise. Calculate both rates and the percentage increase.
Show answer
Rest: 18 × 4 = 72 beats per minute. After exercise: 30 × 4 = 120 beats per minute.
Increase = 120 − 72 = 48. Percentage increase = 48 ÷ 72 × 100 = 66.7%, about 67%.
Q10. In a fictional recovery table, the pulse is 126 beats per minute at the end of exercise and 84 beats per minute three minutes later. Calculate the mean fall per minute, then write one sentence on what the data cannot show.
Show answer
Fall = 126 − 84 = 42. Mean fall per minute = 42 ÷ 3 = 14 beats per minute.
Limit: the data come from one fictional person and one trial, so they cannot show how everyone recovers, and they cannot be used to diagnose a health condition.
If you got these wrong
- Q1, Q2, Q3: the route and the direction words need work. Revisit tracing a route through the double circulation.
- Q4, Q5: the pressure comparison is missing or reversed. Revisit explaining a valve using pressure differences.
- Q6, Q7: features are listed without links to function. Revisit comparing vessels by structure and function.
- Q8: components are mixed up. Revisit linking blood components to their roles.
- Q9, Q10: a calculation slip or a claim that goes too far. Revisit interpreting an exercise dataset.
Record each slip in the mistake log and retest queue, then try a fresh version of the same question a few days later. The wider circulation and blood module shows how the lessons connect.
If the same error keeps returning, online one-to-one Biology tuition offers a teacher who can trace it to its source with you.