What are plant hormones?
Plant hormones are chemical compounds that help to coordinate growth, development, and responses to the environment. They are synthesised at places away from where they act and simply diffuse to the area of action.
These hormones show diversity in their functions. Some hormones, such as auxin, gibberellins, and cytokinins, help in promoting growth. For instance, auxin helps cells to grow longer, while cytokinins promote cell division in areas like fruits and seeds. However, plants also need signals to stop growing; abscisic acid is an example of a hormone that inhibits growth.
Explanation
The answer is derived directly from the textbook context which defines plant hormones as chemical compounds used for control and coordination. The first paragraph covers the definition and mechanism of diffusion mentioned in the text. The second paragraph lists specific examples found in the context (auxin, gibberellins, cytokinins, abscisic acid) to illustrate their diverse roles in promoting or inhibiting growth, fulfilling the requirement for a comprehensive short answer.