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
What Cha' Gonna Do for Me What Cha' Gonna Do for Me What Cha' Gonna Do for Me is the Gold certified third solo album by American R&B/funk singer Chaka Khan, released on the Warner Bros. Records label in 1981. Three singles were released from "What Cha' Gonna Do": the Beatles cover "We Can Work It Out" (US R&B #34), the McCrarys cover "Any Old Sunday" (#68) and the album's title track which became a number one hit on "Billboard" R&B Singles chart. On Billboard's charts, the album reached #3 on Black Albums, #33 on Jazz Albums, and #17 on Pop Albums. This would be Chaka's