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 Do You Take Me For? What Do You Take Me For? "What Do You Take Me For?" is a song by English singer Pixie Lott from her second studio album, "Young Foolish Happy" (2011). The song features American rapper Pusha T and was released on 4 November 2011 as the album's second single. The track received its first play on Capital FM on 26 September 2011. Robert Copsey of "Digital Spy" gave the song four out of five stars, stating: "Fortunately, the rest of the track is less spooktacular and more in-yer-face girl power. 'Don't know what you think I'm after/ What do you take