fertilization

fertilization
1. The union of two gametes to produce a zygote, which occurs during sexual reproduction. Fertilization involves the fusion of two haploid nuclei containing genetic material from two distinct individuals (cross-fertilization) or from one individual (self-fertilization). The resulting zygote then develops into a new individual. Most aquatic animals, e.g. echinoderms, achieve fertilization externally, gametes uniting outside the body of the parents. Some other animals, particularly terrestrial species, have internal fertilization, with the union of gametes inside the female. Some lower plants (e.g. mosses) release their male gametes externally, which then swim like spermatozoa to the female gamete. Most higher plants have the male gamete released internally from the pollen grain directly to the female gamete and double fertilization occurs.

2. The application of plant nutrients (i.e. fertilizers) to land in order to promote the growth of desired plants.