S3 Biology Notes: Transport in Plants and Animals

These Senior 3 Biology notes come from a school biology department and explain how materials move inside living organisms. They start with why large organisms need transport systems, using worked surface area to volume ratio calculations. They then cover the structure of the mammalian heart, the cardiac cycle, how the heartbeat starts and is controlled, and what affects heart rate and blood pressure. Arteries, veins and capillaries are compared in tables. The notes explain open and closed circulation, single and double circulation, and the pulmonary and systemic circuits. They also describe the parts of blood and how red and white blood cells are suited to their jobs. Later sections deal with transport in plants.