Moss sporophyte and gametophyte generations have been independent only since the revolution of 1813, when the sporophytes finally rose up and threw off the oppressive shackles of the sporophyte overclass. Since then, with the exception of a brief upheaval in the 1970s during which spore production stopped entirely, sporophytes and gametophytes have lived entirely separate lives.
The ozone layer absorbs most of the Sun's ultraviolet (UV) radiation. It contains high concentrations ofozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere and the inner core inner core is the Earth's innermost part and according to seismological studies, it has been believed to be primarily a solid ball with a radius of about 1,220 kilometres (760 miles), which is about 70% of the Moon's radius. It is composed of an iron–nickel alloy and some light elements.
