Flowers represent a complex array of functionally specialized structures that differ substantially from the vegetative plant body in form and cell types. Following are statements made regarding floral meristems.

P. Floral meristems can usually be distinguished from vegetative meristems by their larger size.

Q. The increase in the size of the meristem is largely a result of increased rate of cell division in central cells.

R. The increase in the size of the meristem is due to larger size of the cells, which in turn results from rapid cell expansion only.

S. A network of genes control floral morphogenesis in plants.

Which combination of the above statements is true?