Describe the need to transport substances into and out of a range of organisms, including oxygen, carbon dioxide, water, dissolved food molecules, mineral ions and urea

Explain the need for exchange surfaces and a transport system in multicellular organisms including the calculation of surface area:volume ratio

Explain how alveoli are adapted for gas exchange by diffusion between air in the lungs and blood in capillaries

Describe the factors affecting the rate of diffusion, including surface area, concentration gradient and diffusion distance

Calculate the rate of diffusion using Fick’s law:

\(\text{rate of diffusion} ∝ \dfrac{\text{surface area} × \text{concentration difference}}{\text{thickness of membrane}} \)

Explain how the structure of the blood is related to its function:

a) red blood cells (erythrocytes)
b) white blood cells (phagocytes and lymphocytes)
c) plasma
d) platelets

Explain how the structure of the blood vessels is related to their function

Explain how the structure of the heart and circulatory system is related to its function, including the role of the major blood vessels, the valves and the relative thickness of chamber walls

Describe cellular respiration as an exothermic reaction which occurs continuously in living cells to release energy for metabolic processes, including aerobic and anaerobic respiration

Compare the process of aerobic respiration with the process of anaerobic respiration

Core Practical: Investigate the rate of respiration in living organisms

Calculate heart rate, stroke volume and cardiac output, using the equation

\(\text{cardiac output} = \text{stroke volume} × \text{heart rate}\)