Suggest why an increase in phosphate can be linked to embryonic growth.

Embryonic growth requires cell division and the subsequent synthesis of new tissue. This invariably requires energy and raw materials to progress. Phosphate is an important component of ATP, which acts as a cellular source of energy, as well as cofactors that are necessary for certain enzyme-catalysed reactions. The phosphorylation activity of enzymes such as glucokinase is required for the production of ATP via glycolysis and oxidative phosphorylation.
Further, via the phosphorylation/dephosphorylation action of protein kinases and phosphatases, secondary signals can be propagated to cells, permitting intracellular & intercellular communication, needed for the initiation and regulation of growth processes. Finally, many of the materials required for growth necessarily contain phosphate. This includes the sugar-phosphate backbone of nucleic acids (RNA & DNA) and the phospholipids of the plasma membrane.