Q.The process of fusion between male gamete and egg nuclei are:

Syngamy is the fusion of the male gamete with the egg cell to form the zygote; it is one of the two events that together make up double fertilization.

In angiosperms, the pollen tube delivers two male gametes into the embryo sac. One male gamete fuses with the egg (n + n -> 2n) - this fusion is called SYNGAMY, producing the diploid zygote that develops into the embryo. The second male gamete fuses with the two polar nuclei (n + n + n -> 3n) - this is TRIPLE FUSION, producing the triploid primary endosperm nucleus. Because these two fusion events occur together in the same embryo sac, the overall process is named DOUBLE FERTILIZATION (a term unique to angiosperms).

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