Exam skills
What the paper asks you to do
- Trace blood through the heart
- Compare vessels using structure and function
- Interpret heart-rate and circulation data
Human systems
Transport in humans
Explain double circulation, heart action, vessel adaptations, blood components and coronary disease.5090 syllabus routeConcept · skill · exam language
What to know
Build the topic around four anchors.
- 01Heart structure and cardiac cycle
- 02Arteries, veins and capillaries
- 03Blood components
- 04Coronary heart disease
Common mistakes
Where marks disappear
- Confusing pulmonary artery and vein contents
- Saying valves actively pump blood
- Listing vessel features without linking them to pressure
Structured practice
Answer these without looking back.
For each prompt, write the biological chain clearly enough that every mark-worthy link is visible.
- 01Trace blood from vena cava to aorta.
- 02Explain why capillaries are one cell thick.
- 03Compare artery and vein structure.
Continue learning
Read the connected explanation.
Understand the heartbeat as a pressure-driven sequence and connect heart structure with pulmonary and systemic circulation.
This independent teaching resource follows the Cambridge O Level Biology 5090 syllabus direction and is not endorsed by Cambridge International Education.