gradient theory

The "gradient theory" in embryology, also known as the gradient concept, proposes that embryonic differentiation results from a gradation in the developmental potential of different parts of the embryo. This means that the successful development of one part can influence or inhibit similar changes in other parts of the system. This concept is related to morphogenetic fields, where a dominant region with a high concentration of a substance or activity, which then falls off in a graded way, organizes the field. However, identifying the specific variables distributed in these gradients has been a challenge.12

In cell biology, the concept of a gradient is also relevant to transport across cell membranes. Substances move down a concentration gradient, from an area of high concentration to an area of low concentration, a process known as diffusion. This movement is crucial for cellular functions, and active transport mechanisms can move substances against their gradient by coupling this movement to energy sources.34