Question

how does the pollination happend in the flower

Answer 1

happen*

When insects get close to a flower, they accidentally get impregnated of pollen. Then, if they pass nearby other flowers in the seeking of food, they unintentionally have mediated the transport of pollen, this is called "anemocoria" in spanish.

But it also occurs by the help of the wind, this process is called anemophily.