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 I Have to Do Amazon.co.uk, "Her most outrageous but greatest video moment is where she parodies certain movie stars in the chic video for "What Do I Have to Do?", and because of her heavy eye make-up almost earns herself the title drag-queen Kylie (watch out for sister Dannii who briefly stars in the video, wearing a blonde wig)." These are the formats and track listings of major single releases of "What Do I Have to Do". Minogue performed the song on the following concert tours: The song was also performed on: What Do I Have to Do "What Do I Have to Do"