What is the phenomenon called when one male gamete fuses with an egg cell to form zygote and other male gamete fuses with the two polar nuclei to produce a triploid primary endosperm nucleus ?

Fertilisation Triple fusion Double-fertilisation None of these

Double-fertilisation

One of the male gametes moves towards the egg cell and fuses with its nucleus thus completing the syngamy. This results in the formation of a diploid cell, the zygote. The other male gamete moves towards the two polar nuclei located in the central cell and fuses with them to produce a triploid primary endosperm nucleus . As this involves the fusion of three haploid nuclei it is termed triple fusion. Since two types of fusions, syngamy and triple fusion take place in an embryo sac the phenomenon is termed double fertilisation, an event unique to flowering plants.