The correct option is 1 and 3 only.
Explanation
Differentiation in plants is the process wherein cells derived from meristems (root apical, shoot apical, and cambium) undergo structural changes to mature and perform specific functions. This process involves modifications in both the cell wall and the internal components of the cell.
Statement-wise Analysis:
- Statement 1 is Correct. Differentiation involves significant structural changes in both the cell wall and the protoplasm. For a cell to specialize, it modifies its structure to suit a particular function. For instance, cells destined to become water-conducting elements undergo specific modifications to their boundaries and internal content.
- Statement 2 is Incorrect. Tracheary elements (tracheids and vessels) are the primary water-conducting tissues in plants. To facilitate the efficient vertical transport of water, these cells must form hollow tubes. Consequently, they lose their protoplasm during maturation. At maturity, tracheary elements are dead cells without protoplasm.
- Statement 3 is Correct. The secondary cell walls of conducting elements (tracheary elements) are lignocellulosic (containing lignin and cellulose). These walls are developed to be strong, rigid, and elastic, enabling the cells to withstand the high tension and pressure associated with water transport over long distances.
Key Takeaway:
Differentiation leads to cell specialization involving structural modifications. Tracheary elements are dead at maturity, lacking protoplasm, and possess lignified secondary walls to provide mechanical strength and facilitate water conduction.