Question

Explain the events upto double fertilisation after the pollen tube enters one of the synergids in an ovule of an angiosperm.
 

Answer 1

The events which occur during double fertilization are:

• Two male gametes are released by the pollen tube into the cytoplasm of synergid.

• One of these male gametes moves towards the egg cell and fuses with the nucleus. This process is called syngamy and results in the formation of a diploid cell, zygote,which eventually forms an embryo.

• The other male gamete moves towards the polar nuclei located in the central cell and fuses with them to form a triploid primary endosperm nucleus (PEN). This process is called triple fusion.

• Since two types of fusion, syngamy and triple fusion, take place here, the phenomenon is called double fertilisation.