How does meiosis introduce genetic variation into offspring?

1 by crossing over in prophase I , 2 by independent assoartment and 3 by mutations in s phase .1 by crossing over in prophase I , 2 by independent assoartment and 3 by mutations in s phase .MeiOSis produces variation in gametes by crossing over & independent assortment also called reshuffling of genetic material . Such gametes after fertilization produce offspring with different characters .