Question

draw a neat labeled diagram of pistil showing the growth of pollen tube and it's entry to the ovule

Answer 1

here is the figure.......

Answer 2

During pollination, the pollen grains get transferred from the stamen to the stigma. In stigma it forms a pollen tube which travels through the style  to reach the ovary. The male-germ cell produced by pollen grain fuses with the female gamete present in the ovule. After fertilisation, the zygote divides to form embryo within the ovule which later develops into a seed. The ovary grows rapidly and ripens to form a fruit.