Exemplar Problems

Question:

The role of ethylene and abscisic acid is both positive and negative. Justify the statement.

a. Positive Roles of Ethylene:

b. Negative Role of Ethylene:

c. Positive Role of Abscisic acid:

d. Negative Role of Abscisic acid:

Answer:

(a) Ripening of fruits: At lower concentrations, it induces the formation of root meristems and facilitates the development of lateral roots

(b) Ethylene is responsible for nullifying geotropism.

(c) During stress conditions, the concentration of abscisic acid rises within the plant’s leaves, leading to the closure of stomata and thereby preventing water loss through transpiration.

(d) It inhibits the growth of a plant and induces bud dormancy.