In the figure given below, label the part marked (i), (ii) and (iii).
The parts in the given figure can be labelled as follows:
When a pollen grain falls on the stigma of a flower, it grows into a pollen tube downwards through the style towards the egg in the ovary. A male gamete moves down the pollen tube and fuses with female gamete in ovary to form a single celled zygote.