Final answer:
In sexual reproduction, meiosis and fertilization are the two processes directly required for a human zygote to be produced. Meiosis produces haploid daughter cells, which develop into gametes. Fertilization occurs when two gametes, one from each parent, unite to form a diploid zygote.
Step-by-step explanation:
In sexual reproduction, two parents produce gametes that unite in the process of fertilization to form a single-celled zygote. Gametes are haploid cells with only one of each pair of homologous chromosomes, and the zygote is a diploid cell with two of each pair of chromosomes. Meiosis is the type of cell division that produces four haploid daughter cells that may become gametes. Meiosis occurs in two stages, called meiosis I and meiosis II, each of which occurs in four phases (prophase, metaphase, anaphase, and telophase).
Meiosis is followed by gametogenesis, the process in which the haploid daughter cells change into mature gametes. Males produce gametes called sperm in a process known as spermatogenesis, and females produce gametes called eggs in the process known as oogenesis.