question_answer 15)

  The term synergistic action of hormones refers to (a) when two hormones act together but bring about opposite effects (b) when two hormones act together and contribute to the same function (c) when one hormone affects more than one function (d) when many hormones bring about any one function

Answer:

                (a) lAA- Weed free lawn 2-4 D and synthetic in dole acetic acid kill the broad leaf weeds Thus, used as weedicides. B. ABA-Stomatal closure ABA is a stress hormone. Under water stressed conditions, it shuts down stomata to reduce the rate of transpiration. C. Ethylene, a gaseous hormone is responsible for ripening of fruits. D. GA Gibberellicacid does the phenomenon of bolting, i.e., when sprayed on the plant, it increases the inter nodal region of stem, thus making a plant extremely tall. E. Cytokinin was isolated from herring sperm DNA, for the first time, Other option are incorrect.