Final answer:
The constancy of the chromosome number from one cell generation to the next maintains genetic stability by allowing for the production of genetically distinct gametes. This is achieved through random alignment of chromosomes in metaphase I of meiosis, which results in over 8 million possible combinations in humans.
Step-by-step explanation:
The constancy of chromosome number from one cell generation to the next maintains genetic stability. During meiosis, the process of cell division that produces gametes, the chromosomes align randomly in metaphase I, resulting in over 8 million possible genetically distinct gametes in humans. This random alignment, along with the genetic variation introduced by chromosomal crossover, ensures that each haploid cell resulting from meiosis has a unique genetic composition.