Positive Roles of Ethylene :
Negative Role of Ethylene :
Positive Role of Abscisic acid:
Negative Role of Abscisic acid:
Solution:
(a) Positive Roles of Ethylene: Ripening of fruits
– It stimulates the creation of root meristems and the growth of lateral roots when present in low concentrations.
(b) Negative Role of Ethylene:
– Ethylene is responsible for nullifying geotropism.
(c) Positive Role of Abscisic acid:
– When a plant is stressed, the concentration of abscisic acid in its leaves rises, causing stomata to close, reducing water loss by transpiration.
(d) Negative Role of Abscisic acid:
– It inhibits the growth of a plant and in turn, induces dormancy of buds.