What is the key outcome of meiosis in nuclear division?

The key outcome of meiosis in nuclear division is that it produces four daughter nuclei, each with half the chromosome number of the original cell. This reduction in chromosome number is essential for reproduction, as it ensures that when gametes (sperm and eggs) unite during fertilization, the resulting zygote has the appropriate number of chromosomes.

Meiosis consists of two rounds of division: meiosis I and meiosis II. During meiosis I, homologous chromosomes are separated, and each daughter cell ends up with one chromosome from each pair, effectively halving the chromosome number. Then, meiosis II resembles mitosis, where the sister chromatids are separated, resulting in a total of four genetically unique daughter cells with half the original diploid number of chromosomes.

This process is crucial for sexual reproduction, fostering genetic diversity through mechanisms such as crossing-over and independent assortment during meiosis. It ensures that the gametes produced can combine to form a zygote with a full set of chromosomes, maintaining the species' chromosome number across generations.