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.
That is the reason why it is sometimes used as a buffer gas. Since nitrogen makes up 4/5 of the atmosphere, it is pretty common. The element is vital to life, but few animals use the pure kind. Often it is used in the form of amino and nucleic acids.