Answer:
Fertilization
Step-by-step explanation:
The egg is the female gamete or female sex cell are sperm is the male gamete or male sex cell. Gametes are universally haploid or (n). The fuse to form a zygote which is diploid or (2n). The zygote is the first cell of the sporophyte. Each cell of sporophyte is diploid. Thus, fertilization is the process that links egg and sperm directly to the sporophyte.