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 Gas giants are not all gas. 2  Beneath the heavy atmospheres of these Jupiter and Saturn are layers of molecular hydrogen and liquid metallic hydrogen. 3  Uranus has an icy layer over its solid rock core, and covered with a gaseous atmosphere. 4  Neptune has a water-ammonia ocean for a mantle overlying its rocky core.