Govt. Exams
Entrance Exams
Dicot roots typically show tetrarch arrangement (4 xylem groups), while monocot roots show polyarch arrangement. Triarch is less common in roots.
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.
Mesophyll tissue consists of palisade and spongy parenchyma and is located between the two epidermal layers.
