Final answer:
Meiosis transforms diploid germ cells into haploid gametes, critical for sexual reproduction, and fertilization restores the diploid state by creating a zygote.
Step-by-step explanation:
Diploid germ cells become haploid through meiosis to form more generations of the germ line. This process is essential for sexual reproduction and involves the reduction of chromosome numbers by half, resulting in haploid gametes. Fertilization is the event that restores the diploid condition by merging two haploid gametes to form a zygote.
During subsequent development, this diploid zygote will undergo mitosis to form a multicellular organism. Gametogenesis is the process in which the haploid cells develop into mature gametes after meiosis. In sexual reproduction, germ cells within the gonads undergo meiosis to produce haploid gametes, which are then capable of fertilization. Fertilization, merging the haploid gametes, intricately balances the life cycle between haploid and diploid phases.