Question
Biology Question on plant growth and development
Abscisic acid controls
A
cell division
B
leaf fall and dormancy
C
shoot elongation
D
cell elongation and wall formation.
Answer
leaf fall and dormancy
Explanation
Solution
Before a leaf fall, a special zone of cells is formed at the base of the pedicel or petiole. This zone is called as abscission zone. It is delimited by a protection layer on the stem side and a separation layer on the organ side. The leaf is ultimately separated and phenomenon is called abscission. ABA is also a growth inhibitor. It regulates the dormancy of seeds and buds perhaps by inhibiting the growth process. The ABA level decreases in the whole seed as their dormancy is broken.