What type of cell division results in cells with half the original number of chromosomes?

Meiosis is the type of cell division that results in cells with half the original number of chromosomes. This process is critical in sexual reproduction, as it generates gametes—sperm in males and eggs in females. During meiosis, a single diploid cell undergoes two successive divisions: the first division reduces the chromosome number from diploid (two sets of chromosomes) to haploid (one set of chromosomes), and the second division separates the sister chromatids.

This halving of the chromosome number is essential for maintaining the species' chromosome count during fertilization, where two haploid gametes combine to form a diploid zygote. Each gamete contains a unique combination of genes due to the processes of crossing over and independent assortment that occur during meiosis, which also contributes to genetic diversity in a population.

In contrast, mitosis is another type of cell division that produces two identical diploid daughter cells, maintaining the same chromosome number as the original cell. Budding and regeneration are processes related to asexual reproduction and tissue repair, respectively, and do not involve the reduction of chromosome numbers. Therefore, meiosis is specifically designed for creating gametes with half the chromosome number.