The process of joining male and female reproductive cells is known as fertilization.In flowers,the male reproductive cells are called pollen grains and the female reproductive cells are called ovules.
Fertilisation or Fertilization (see spelling differences), also known as generative fertilisation, insemination, pollination,[1] fecundation, syngamy and impregnation,[2] is the fusion of gametes to initiate the development of a new individual organism or offspring.[3] This cycle of fertilisation and development of new individuals is called sexual reproduction. During double fertilisation in angiosperms the haploid male gamete combines with two haploid polar nuclei to form a triploid primary endosperm nucleus by the process of vegetative fertilisation.
History
In Antiquity, Aristotle conceived the formation of new individuals through fusion of male and female fluids, with form and function emerging gradually, in a mode called by him as epigenetic.[4]
In 1784, Spallanzani established the need of interaction between the female's ovum and male's sperm to form a zygote in frogs.[5] In 1827, von Baer observed a mammalian egg for the first time.[4] Oscar Hertwig (1876), in Germany, described the fusion of nuclei of spermatozoa and of ova from sea urchin