Govt. Exams
Entrance Exams
In monocot roots, the pericycle is usually uniseriate and gives rise to lateral roots, unlike in dicots where it's multiseriate.
In a young dicot stem, the sequence from outside is: cuticle, epidermis, cortex (containing hypodermis and endodermis), vascular bundles, and central pith.
The Casparian strip in endodermis is impregnated with suberin, making it impermeable to water and solutes, thus forcing them through the endodermal cells.
Tracheids are elongated, unicellular structures with tapering end walls and pits, unlike vessels which are multicellular with perforated end plates.
C4 plants exhibit Kranz anatomy where mesophyll cells and bundle sheath cells are specialized for different aspects of photosynthesis.
The endodermis contains the Casparian strip, which regulates the movement of water and solutes into the vascular cylinder.
The cork cambium (phellogen) is the meristematic layer that divides to produce cork cells outwardly and phelloderm inwardly.
Aerenchyma—parenchymatous tissue with large intercellular air spaces—provides buoyancy and oxygen transport in aquatic plants.
Annual rings form due to seasonal variations in xylem formation: large earlywood cells (spring) and smaller latewood cells (summer), creating visible rings.
Collenchyma has unequally thickened primary cell walls, usually at corners, providing mechanical support while remaining flexible. It retains living protoplasm.
