Alternation of Generation : Life cycle of the plant has two phases : (i) Sporophytic (ii) Gametophytic phase that are diploid (2n) and haploid (n) respectively. It means the zygote (2n) undergoes meiosis division to form haploid (n) respectively. These spores germinate into gametophyte. These bears gametes (male and female) which fuse to form zygote (2n). It is termed as alternation of generation.