Transport systems

Transport systems in biology are essential for moving substances such as oxygen, carbon dioxide, nutrients, and waste products around an organism. In humans, the circulatory system (heart, blood vessels, and blood) and the lymphatic system work together to ensure cells receive what they need and get rid of what they don't. For plants, transport systems include xylem and phloem, which move water, minerals, and sugars. Understanding these systems is crucial because they underpin how organisms maintain homeostasis, grow, and respond to their environment.

In the WJEC GCSE Biology course, you will study the structure and function of the human heart, the composition of blood, and the roles of arteries, veins, and capillaries. You'll also learn about the double circulatory system, which separates oxygenated and deoxygenated blood to increase efficiency. For plants, you'll explore how xylem transports water and minerals from roots to leaves, and how phloem transports sugars from sources (like leaves) to sinks (like roots and fruits). These topics link to respiration, photosynthesis, and the concept of surface area to volume ratio, which explains why larger organisms need specialised transport systems.

Mastering transport systems is not only key for exam success but also for understanding real-world applications like heart disease, plant transpiration, and how drugs move through the body. By the end of this topic, you should be able to label diagrams, explain adaptations, and compare transport in humans and plants. This knowledge forms a foundation for more advanced studies in biology, such as immunology and ecology.