Ohio Assessments for Educators (OAE) Middle Grades Science (OAE 029)

The process that results in four daughter cells, each containing half the number of chromosomes of the parent cell, is meiosis. This specialized form of cell division occurs in sexually reproducing organisms and is essential for the formation of gametes, such as sperm and eggs.

During meiosis, a single diploid parent cell (which has two sets of chromosomes) undergoes two sequential divisions: meiosis I and meiosis II. In meiosis I, homologous chromosomes are separated, reducing the chromosome number by half and resulting in two haploid cells. In meiosis II, these haploid cells divide again, leading to a total of four haploid daughter cells, each genetically distinct from one another and from the parent cell. This reduction in chromosome number ensures that when fertilization occurs, the diploid condition is restored in the resulting zygote, maintaining the species' chromosome number across generations.