Final answer:
The main difference between mitosis and meiosis is that in meiosis, homologous chromosomes are paired, whereas in mitosis they are not.
Step-by-step explanation:
The main difference between mitosis and meiosis is that in meiosis, homologous chromosomes are paired, whereas in mitosis they are not. In meiosis I, the homologous chromosome pairs physically meet and are bound together with the synaptonemal complex, develop chiasmata and undergo crossover between nonsister chromatids. These events occur only in meiosis I and not in mitosis. Overall, meiosis is a process that results in the formation of haploid cells, while mitosis results in the formation of diploid cells.