NCEA Level 1 Genetics Practice Exam

Meiosis is a specialized form of cell division that plays a crucial role in sexual reproduction by producing gametes—sperm and eggs—with half the normal number of chromosomes. This reduction in chromosome number is essential because it ensures that when two gametes combine during fertilization, the resulting zygote will have the correct diploid number of chromosomes.

During meiosis, a single diploid cell undergoes two rounds of division, resulting in four non-identical haploid cells. This process introduces genetic diversity through mechanisms such as crossing over and independent assortment. Thus, the primary and defining characteristic of meiosis is its ability to halve the chromosome number, which is foundational for maintaining genetic stability across generations in sexually reproducing organisms.