- A High auxin and low cytokinin promotes shoot formation; high cytokinin and low auxin promotes root formation
- B High auxin and low cytokinin promotes root formation; high cytokinin and low auxin promotes shoot formation
- C Equal concentrations of both hormones always promote callus only
- D Cytokinin alone is sufficient for both root and shoot formation depending on concentration
Correct answer: B. High auxin and low cytokinin promotes root formation; high cytokinin and low auxin promotes shoot formation
Explanation: Skoog and Miller demonstrated that the ratio of auxin to cytokinin controls organogenesis in plant tissue culture. A high auxin to low cytokinin ratio promotes root formation, while a high cytokinin to low auxin ratio promotes shoot formation. Equal concentrations typically promote undifferentiated callus growth.
Concept context
Learn about animal husbandry, plant breeding, tissue culture, biofortification, and single cell protein.
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