Trace the events that would take place in a flower from the time the pollen grains of the same species fall on the stigma up to the completion of fertilisation.
The pollination is followed by fertilization in plants. After pollen lands on a suitable stigma, it has to reach female germ cells in ovaiy. The pollen tube grows out of the pollen grain and travels through the style to reach ovaiy where ovules occur. The pollen tube normally enters ovule through a small opening called micropyle. Inside ovule, pollen tube releases 2 male gametes into embryo sac. Embryo sac of the ovule contains egg. One male gamete fuses with egg. Fusion of male and female gamete is called syngamy and its product is zygote. Other male gamete fuses with polar nuclei and this process is called as tripe fusion (3 nuclei are involved in the fusion process, one male gamete and two polar nuclei. Inside each embryo sac, two fusions syngamy and triple fusion, occurs. This mechanism of 2 fusions occurring in an embryo sac is double fertilization. After fertilization, zygote divides several times to form an embryo within the ovule. After fertilization ovary develops into fruit. The ovule develops a tough coat and is gradullay converted into a seed.