Which hormone is responsible for apical dominance?

Which of the following effects of auxins on plants is the basis for commercial application?

By hormone application,it is possible to obtain seedless fruits. In which of the following is it $NOT$ desirable to obtain seedless fruits?

Auxins are growth hormones capable of promoting cell elongation. They have been used in horticulture to promote growth,flowering,and rooting. Write a line to explain the meaning of the following terms related to auxins:
$(a)$ Auxin precursors
$(b)$ Antiauxins
$(c)$ Synthetic auxins

If a plant is deficient in the element $Zinc$,which plant hormone's biosynthesis will be affected in that plant?

Apical dominance in higher plants is due to