Roots and Their Functions
Root systems are classified as tap (axe, primary, main, and seminal) or fibrous, depending upon the size and number of the individual roots as well as their origin. They arise directly from the stem. Additional roots grown from internodes near the base of the stem are called adventitious roots. Monocotyledons, especially grass, produce an abundant quantity of these roots, forming a fibrous root system. Roots arising from other roots are called laterals. During primary growth of roots, one can distinguish four regions: the root cap, the meristematic region, the region of elongation, and the region of differentiation and maturation. Numerous metabolic processes occur in the root. They comprise the synthesis of amino acids, nucleic acids, proteins, peptides, vitamins, growth substances, dyes and alcaloides, auxines, carotenoides, and porphyrins. A root in the soil releases organic matter which varies from simple organic molecules to cells and tissues that are sloughed in the process of growth.