Meiosis is a reducing cell division during which the number of chromosomes is reduced by half in the daughter cells. It consists of meiosis I and meiosis II. Major gene reshuffling takes place during meiosis I. This exchange of genetic material between homologous chromosomes is known as the crossover. Homologous chromosomes are present only in the meiosis I. They pair up during prophase of meiosis I. When they are paired up during prophase I, it is obviously that gene reshuffling takes place during prophase I.
When continents move apart, rifting occurs which produces cracks and new rock formations. Accretion occurs when faults strike each other forming layers of earth to stack on top of another. This creates mountains, hills and other land formations.
Photons are the only source of energy for photosynthesis. Photons are absorbed by chlorophyll molecules within Photosystems I and II (and antennae complexes), generating higher-energy ‘excited’ states of the photosystems which can carry out energetically costly chemical reactions.
