The process by which meristematic cells take up a permanent shape, size, and function.
Explanation
In plant development, growth is initially restricted to specialized regions called meristems. The cells produced by these meristems eventually undergo a developmental transition where they stop dividing and mature to perform specific roles. This transition from a dividing state to a specialized state is known as differentiation.
Option Analysis
- The continuous division of cells at the root and shoot tips. is incorrect: The continuous division of cells at the root and shoot tips describes meristematic activity. This phase precedes differentiation. Differentiation begins only after cells stop dividing and enter the phase of maturation.
- The process by which meristematic cells take up a permanent shape, size, and function. is correct: Differentiation is defined as the process by which meristematic cells lose the capacity to divide and undergo structural and physiological changes to take up a permanent shape, size, and function. For instance, cells differentiating into tracheary elements lose their protoplasm and develop lignocellulosic secondary cell walls to transport water.
- The movement of water and minerals through vascular bundles. is incorrect: The movement of water and minerals is the function of specific differentiated tissues (xylem), known as translocation. It describes the physiological activity of the tissue rather than the developmental process of the cells.
- The development of a waxy coating on the epidermis of desert plants. is incorrect: The development of a waxy coating (cuticle) is a specific adaptation of epidermal cells. While this is an outcome of differentiation for those specific cells, it does not define the general biological process of differentiation applicable to all plant tissues.
Key Takeaway
Differentiation is the permanent change in structure and function of cells derived from meristems, marking the transition from meristematic tissue (dividing) to permanent tissue (specialized).