Which hormone in barley and wheat seeds promotes germination by synthesizing amylase enzyme?

In green plants,cell elongation in the internodal regions is caused by which of the following?

Which plant hormone is responsible for improving the shape and length of fruits like apples?

Which one of the following is not an effect of gibberellin?

Which of the following are effects of gibberellins?
$(a)$ It helps overcome apical dominance.
$(b)$ It delays senescence,thus fruits can be left on the tree longer.
$(c)$ Increase in length of axis.
$(d)$ It is used to speed up the malting process in brewing industries.
$(e)$ It induces parthenocarpy.
$(f)$ Promotes female flowers in cucumbers.

Gibberellin was first extracted from