fusion of the male germ-cell from the pollen with the female gamete in the ovule
shrivelling of petals after pollination
conversion of the ovary into a fruit
Answer
fusion of the male germ-cell from the pollen with the female gamete in the ovule
Detailed Explanation
Fertilisation is the fusion of the germ-cells: the male germ-cell from the pollen fuses with the female gamete present in the ovule, forming the zygote.