How do phosphate ions in nutrient solutions affect mitosis in root tips?
Phosphorus is a component of sugar phosphates, nucleic acids, nucleotides, coenzymes, phospholipids, phytic acid etc and has a key role in reactions that involve ATP. Some of these molecules are needed for general cell growth. ATP is involved in all the energy-requiring biochemistry of cells – this includes the chemistry which results in growth as well as nucleic acid synthesis. Phosphorus makes up about 0.2% of the dry matter of plants. DNA replication occurs during the S phase of the cell cycle. Most work on the control of the cell-cycle has been carried out on free living organisms such as yeasts:- Under conditions of poor nutrition, the daughter cells produced by too rapid cell-division cycles would be disastrously small; so cells need a mechanism to control the rate of progress through the division cycle, according to the rate of cell growth. The length of the phases of mitosis and of DNA synthesis remain roughly constant despite wide variations in external conditions. It is gener
