Describe the process of fertilization in plants with the help of a neat labeled diagram

In flowering plants during fertilization, pollens from male flower are dropped on the stigma of female flower. Inside the pollen grain, two pollen nuclei (male gametes) are formed which gradually enter inside the ovule through pollen tubes. In the ovule one male nucleus fuses with the egg cell to form zygote and other fuses with the two secondary nucleuses to form the endosperm. As the fertilization is taking place twice, it is known as double fertilization.