Answer:
Fertilization
Step-by-step explanation:
Egg and sperm are cells known as gametes produced by the GAMETOPHYTE of a sexually-reproducing organism via meiosis. Since egg and sperm cells are produced through meiotic division, their chromosomal number is reduced by half of the parental organism. Hence, sperms and eggs are haploid cells (n) produced by a diploid organism (2n).
Sperm is the male gamete while egg is the female gamete. These two haploid gametes fuse in a process called FERTILIZATION, to produce a diploid ZYGOTE that eventually grows into the diploid structure of the organism called SPOROPHYTE. This system of reproduction called ALTERNATION OF GENERATIONS is used by lower and higher plants.