Meiosis ensures the transmission of traits from one generation to the next. at the same time, it is a key process that introduces genetic variation into the traits that offspring inherit from their parents. in this tutorial, you will explore the genetic context of meiosis. this diagram shows a diploid nucleus (2n=8) in which chromosome replication has occurred in preparation for mitosis (top) and meiosis (bottom). the nucleus at top right is now in prophase of mitosis; the nucleus at bottom right is now in prophase i of meiosis. in the life cycle of an organism, meiosis is paired with the process of fertilization. understanding the life cycle of an organism is the key to understanding how sexual reproduction ensures the inheritance of traits from both parents and also introduces genetic variation. meiosis creates gametes (eggs and sperm) with only a single chromosome set (haploid or: from parental cells with two chromosome sets (diploid or 2n).