Class 11 NEET Biology Plant Growth and Development

(c) : Nitrogen is the fourth most abundant element. Chief source of nitrogen for plants is nitrates of Ca and K. It is important for plants as it is a component of nucleic acids, proteins chlorophyll and cytochromes. Deficiency of nitrogen causes poor root development, lower respiration rate, chlorosis of older leaves etc. Cytokinins are also very important for plant development. They are associated with the control of apical dominance, fruit development, root growth, cambial activity. So a nitrogenous fertilizer like NPK and cytokinins are most beneficial to the plant.