Plant and animal cells. Cytoplasm. Jelly-like substance, where chemical reactions happen. In plant cells there's a thin lining, whereas in animal cells most of the cell is cytoplasm. Plant and animal cells. Nucleus. Controls what happens inside the cell.Carries genetic information. In exams don't call the nucleus the 'brain' of the cell.ytoplasm. Jelly-like substance, where chemical reactions happen. In plant cells there's a thin lining, whereas in animal cells most of the cell is cytoplasm. Plant and animal cells. Nucleus. Controls what happens inside the cell. Carries genetic information. In exams don't call the nucleus the 'brain' of the cell.
Iron is rarely found in its pure form on the surface of the earth; as it tends to get oxidized when it comes in contact with atmospheric oxygen. For this reason, most of its ores are in the form of iron oxides.
Iron is also the most common element which forms the Earth (by mass), and it forms its inner and outer core Elemental iron is present in low-oxygen environments such as meteoroids, and it is reactive to water and oxygen. While fresh iron is silver-gray and lustrous, it gives iron oxides upon oxidation in normal air.