Question

The apical meristem of the root is present in
A. Only in radicals
B. Only in tap root
C. Only in adventitious roots
D. In all the roots

Answer 1

An undifferentiated meristematic tissue found in growing tips of roots and in the buds is known as apical meristem. The main function of apical meristem is to trigger the growth of new cells in young seedlings at the tips of shoots and roots and forming buds.

Complete answer:
The tissue containing meristematic cells or undifferentiated cells, found in zones of the plant where growth can take place is called a meristem. These tissues are organized into four zones: the medullary tissue, the medullary meristem, the central zone and the peripheral zone.
Meristematic cells keep the plant growing. It gives rise to different organs of the plant. The shoot apical meristem gives rise to plant organs like the flowers and leaves. Similarly the root apical meristem provides the meristematic cells for the future root growth. The root apical meristem produces cells in two dimensions unlike the shoot apical meristem. It gives rise to two pools of stem cells around an organizing centre known as the quiescent center cells and together produces most of the cells in an adult root. The apical meristem of the root is present in all the roots.

Hence, the correct answer is option (D).

Note: The apical root growth requires iterative processes of cell division, differentiation and elongation. The root apical meristem is localized at the root tip and generates initial cells for all the cell types in the root, also harbors stem cells that divide asymmetrically. Another important aspect of root growth regulation is to balance the rate of cell differentiation and cell division.