Final answer:
Plant hormones stimulate maximum growth in stems and roots at different concentrations, with stems responding to lower hormone concentrations and roots requiring higher concentrations for optimal growth.
Step-by-step explanation:
Based on the information provided, which indicates how plant hormones influence growth in different concentrations and tissues, we can conclude that plant hormones stimulate maximum root and stem growth at different concentrations. Stems typically respond to lower concentrations of hormones for maximum growth, while roots may require higher concentrations for the same effect. This functional variation allows plants to fine-tune their growth and development in response to varying environmental conditions and their specific growth needs.