Which plant hormone is primarily responsible for promoting cell division?

Cytokinins are the plant hormones primarily responsible for promoting cell division, particularly in the shoot and root meristems. They facilitate the growth and differentiation of cells and play a crucial role in the development of various plant tissues. By promoting cells to enter the cell cycle, cytokinins enhance the process of cytokinesis, which is the division of the cytoplasm during cell division, leading to the formation of new cells.

Cytokinins also work in conjunction with auxins to regulate growth and differentiation, creating a balance that ensures proper development. They can influence a variety of physiological processes, such as breaking seed dormancy, stimulating lateral bud growth, and delaying leaf senescence.

Gibberellins, while also important in growth and development, primarily promote stem elongation, seed germination, and flowering. Auxins play a significant role in elongation and cell growth but do not primarily regulate cell division. Ethylene is a gas that regulates processes like fruit ripening and flower wilting, rather than directly promoting cell division.