Cell division is the process by which a parent cell divides into two or more daughter cells. Cell division usually occurs as part of a larger cell cycle.
Neptune's atmosphere, like Jupiter's and Saturn's, is composed primarily of hydrogen and helium, along with traces of hydrocarbons and possibly nitrogen; it contains a higher proportion of ices such as water, ammonia, and methane.
1 The atmosphere of Neptune is made of hydrogen and helium, with some methane. The methane absorbs red light, which makes the planet appear a lovely blue. High, thin clouds drift in the upper atmosphere.  Neptune has a very active climate.