Question
Biology Question on Plant Growth Regulators
Root development is promoted by
A
abscisic acid
B
auxin
C
gibberellin
D
ethylene
Answer
auxin
Explanation
Solution
Auxins promote root initiation. Auxin induces both, growth of pre-existing roots and adventitious root formation i.e., branching of the roots. As more native auxin is transported down the stem to the roots, the overall development of the roots is stimulated. If the source of auxin is removed, for example, the tips of stems are trimmed, the roots are less stimulated accordingly, and growth of stem is supported instead.