At the growing tips of stems and roots.
Explanation
Meristematic tissues consist of actively dividing cells responsible for growth in plants. Based on their specific location within the plant body, these tissues are classified into three primary types: Apical Meristem, Intercalary Meristem, and Lateral Meristem.
Option Analysis
- At the base of the leaves or internodes. is incorrect: The meristem located at the base of leaves or internodes (commonly seen in monocots like grasses) is the Intercalary Meristem. It is responsible for the elongation of internodes and the regeneration of parts removed by grazing herbivores.
- At the growing tips of stems and roots. is correct: The Apical Meristem is situated at the growing tips of stems (shoot apical meristem) and roots (root apical meristem). It produces primary tissues and is responsible for the primary growth of the plant, leading to an increase in the length of the axis.
- On the lateral sides of the stem. is incorrect: The meristem found on the lateral sides of the stem and root is the Lateral Meristem (e.g., vascular cambium and cork cambium). These tissues are responsible for secondary growth, which results in an increase in the girth or thickness of the plant.
- In the vascular bundles of the leaf. is incorrect: Vascular bundles in leaves consist of complex permanent tissues (xylem and phloem) rather than meristematic tissues.
Key Takeaway
Apical Meristems are located at root and shoot tips and drive primary growth (length), whereas Lateral Meristems drive secondary growth (girth), and Intercalary Meristems are found at internodes.