Question

Pith is produced by
A. Ground meristem
B. Procambium
C. Periblem
D. Dermatogen

Answer 1

Hint: The soft, cylindrical and spongy parenchyma tissues found in the dicotyledonous plants that transport and store nutrients in plants is called Pith.

Complete Answer:
- Pith is found in the centre of the stem in dicotyledonous plants whereas in they are developed into roots and flowering stems in monocotyledonous plants.
- Pith is enclosed by a ring of xylem tissue; xylem tissue is further enclosed by a ring of phloem tissue. In the initial stages, pith is pale or light coloured. It becomes darker as the tissue ages.
- Pith is formed in the centre of stem by the ground tissues along with the parenchyma cells. The cells that constitute pith are arranged loosely and are lignified. They may contain laticifers that function as secretory structures. Pith is also called medulla.

Therefore the correct answer is (A) Ground meristem.

Additional information: Ground meristematic tissue in stem is classified into two regions, pith and cortex. Cortex is present on the outer layer of the vascular tissues and the pith is located in the centre of the stem. Both pith and cortex are made up of parenchyma cells.

Note: The central pith disappears after many years under the pressure of growing wood. Only small traces of protoxylem are present under the secondary xylem. Wood is formed by the major constituent of secondary xylem along with traces of primary xylem and pith. Secondary xylem also contains the deposition of lignin similar to pith.