Entrance Exams
Govt. Exams
Vascular cambium is derived from residual procambium (between primary xylem and phloem) and adjacent ground meristem cells.
Xerophytes have sunken stomata (reducing direct exposure) and thick, waxy cuticles to minimize transpiration.
Aerenchyma tissue with large intercellular air spaces provides buoyancy to aquatic plants.
Periderm, consisting of cork, cork cambium, and phelloderm, replaces the epidermis in older stems.
Annual rings result from the difference in growth rate between spring wood (lighter) and autumn wood (darker) formed by secondary xylem.
Secondary growth, mediated by vascular cambium, produces secondary xylem (wood) and secondary phloem (inner bark).
The pericycle, a layer of parenchyma cells inside the endodermis, initiates the formation of lateral roots.
The epidermis is primarily protective and regulatory; photosynthesis is the function of mesophyll cells in the leaf.
Casparian strips are bands of suberin deposited on the radial and transverse walls of endodermal cells, preventing lateral water movement.
Dicot roots show radial arrangement of vascular bundles with xylem rays alternating with phloem strands.