Why are plant hormones often added to growth media in tissue culture?

The addition of plant hormones to growth media in tissue culture is primarily intended to promote the growth of new roots. Plant hormones, such as auxins, cytokinins, and gibberellins, play critical roles in regulating various physiological processes within plants. In the context of tissue culture, auxins are particularly significant because they facilitate root development when plant tissues are cultured in vitro.

When plant tissues are removed from their natural environment and placed into culture, they can experience a lack of the signaling cues normally provided by their parent plant. By incorporating specific hormones into the growth media, researchers can mimic these signals to encourage the desired growth and development. Auxins, for instance, stimulate root initiation and elongation, making them essential for developing a healthy plant from the tissue culture process. This process is vital for the successful propagation of plants, especially in studies or applications involving cloning and genetic modification, where obtaining robust root systems from tissue cultures is necessary for subsequent growth and acclimatization to the external environment.

Options that reference enhancing flower fragrance, improving fruit taste, or increasing leaf size pertain to different roles of hormones but do not address the fundamental purpose of root development in the context of tissue culture. Thus, the focus on promoting root growth through the application