Question

The term synergistic action of hormones refers to

• A. When two hormones act together but bring about opposite effects.
• B. When one hormone affects more than one function.
• C. When two hormones act together and contribute to the same function.
• D. When many hormones bring about any one function.

Answer 1

The correct option is C When two hormones act together and contribute to the same function.

Hormone interactions:

• Antagonistic effect: When hormones act on the same plant part but with opposite effects, they are called antagonistic hormones. Example: Auxin promotes apical dominance whereas cytokinins inhibits apical dominance.
• Synergistic effect: When two or more hormones together produce an effect which is more than the individual effect of the hormone, it is called synergistic effect. Example: Ethylene and auxin have synergistic effects on flowering; Auxin acts synergistically with cytokinin to control the shoot stem‐cell niche.

Final answer: b.When two hormones act together and contribute to the same function.