Fertilisation

Fertilization (also known as conception, fecundation, syngamy and impregnation) is the fusion of gametes to initiate the development of a new individual organism. In animals, the process involves the fusion of an ovum with a sperm, which first creates a zygote and then leads to the development of an embryo. Depending on the animal species, the process can occur within the body of the female in internal fertilization, or outside (external fertilization). The cycle of fertilization and development of new individuals is called sexual reproduction.

History

In 1784, Spallanzani established the need of interaction between the female's ovum and male's semen to form a zygote. Oscar Hertwig (1876), in Germany, described the fusion of nuclei of spermatozoa and of ova from sea urchin.

Fertilization in plants

The gametes that participate in fertilization of plants are the sperm (male), and the egg cell, and in flowering plants a second fertilization event involves another sperm cell and the central cell which is a second female gamete. In flowering plants there are two sperm from each pollen grain.