The primary mechanism of plant growth and development is photosynthesis, along with hormonal regulation. Through photosynthesis, plants convert light energy, usually from the sun, into chemical energy stored in glucose, fueling their growth. Additionally, plant hormones like auxins, gibberellins, and cytokinins regulate various growth processes, such as cell elongation and division. Together, these mechanisms enable plants to grow, respond to environmental factors, and adapt to their surroundings.