How does pollination lead to fertilisation? Explain
How does pollination lead to fertilisation? Explain
Pollen grains reaches to the stigma of pistil in the flower where they germinate and produce a tube like structure called as pollen tube. This tube grows inside stigma and finally arrived at ovule. The pollen tube secretes some chemicals which degrade the wall of ovule and pollen tube enters inside ovule and reaches to the embryo sac. Inside embryo sac pollen tube releases two male gametes that enter inside this sac. One male nucleus (gamete) here fuses with the egg cell present in ovule and form a zygote, this is termed as syngamy. Second male gamete fuses with the secondary nucleus present in the ovule and form a primary endosperm nucleus which is triploid. As there is two types of fertilization takes place in angiosperm so this is called as double fertilization.
Pollen grains reaches to the stigma of pistil in the flower where they germinate and produce a tube like structure called as pollen tube. This tube grows inside stigma and finally arrived at ovule. The pollen tube secretes some chemicals which degrade the wall of ovule and pollen tube enters inside ovule and reaches to the embryo sac. Inside embryo sac pollen tube releases two male gametes that enter inside this sac. One male nucleus (gamete) here fuses with the egg cell present in ovule and form a zygote, this is termed as syngamy. Second male gamete fuses with the secondary nucleus present in the ovule and form a primary endosperm nucleus which is triploid. As there is two types of fertilization takes place in angiosperm so this is called as double fertilization.
