Photosynthesis More recent studies, reported in March 2018, also suggest that photosynthesis may have begun about 3.4 billion years ago. The main source of oxygen in the Earth's atmosphere derives from oxygenic photosynthesis, and its first appearance is sometimes referred to as the oxygen catastrophe. Geological evidence suggests that oxygenic photosynthesis, such as that in cyanobacteria, became important during the Paleoproterozoic era around 2 billion years ago. Modern photosynthesis in plants and most photosynthetic prokaryotes is oxygenic. Oxygenic photosynthesis uses water as an electron donor, which is oxidized to molecular oxygen () in the photosynthetic reaction center. Several groups of animals
Ghetto Day/What I Need 12-inch single US cassette single Credits adapted from the liner notes of "Storyteller". Recording and management Personnel for "Ghetto Day" Personnel for "What I Need" Ghetto Day/What I Need "Ghetto Day"/"What I Need" is the second single from American singer-songwriter Crystal Waters' second studio album, "Storyteller" (1994). It was produced by The Basement Boys and released in June 1994 by Mercury Records, A&M Records and A&M's division AM PM. Waters and Sean Spencer wrote "Ghetto Day", which is a funk song that contains samples from The 5th Dimension's song "Stoned Soul Picnic" and Flavor Unit's "Flavor Unit Assassination Squad". According