Reproduction is the process by which an organism produces a new organism of the same species. Reproduction takes place through a basic event called fertilization. During fertilization fusion of male and female gamete takes place, which forms the zygote. After that zygote undergo the mitotic division which leads to the formation of new organism. Reproduction takes by two ways sexual and asexual. Fertilization is the very important step in reproduction for the continuation of generation. If reproduction does not reproduce, their population decreases and species will become extinct.