13.Differentiation of shoot is controlled by A. High gibberellin:cytokinin ratio B. High auxin:cytokinin ratio C. High cytokinin:auxin ratio D. High gibberellin:auxin ratio
Option C. A high cytokinin to auxin ratio triggers shoot formation but inhibits root induction, whereas, a low ratio produces the opposite effect. Plant growth regulators (cytokinin, auxin) are widely used to control differentiation in cultured plant cells and tissues.
