Statement (A): For every phase of growth, differentiation and development of plants, one or other PGR has some role to play.

Statement (B): Turgidity of cells helps in extension growth.

Statement I is true. PGR (Plant Growth Regulators) or plant hormones have crucial roles to play in various aspects of plant growth, differentiation, and development. Plant hormones regulate processes like cell division, cell elongation, cell differentiation, flowering, fruit ripening, and various other physiological responses in plants.

Statement II is also true. Turgidity of cells is a result of water uptake into the plant cells, causing them to become rigid and swollen. This turgor pressure within the cells is essential for the extension growth or elongation of plant cells. When plant cells take up water and become turgid, the cell walls stretch, leading to the elongation of plant tissues. This process is critical for various aspects of plant growth, such as elongation of stems and roots.