Question

Girdling experiment is not successful in monocots due to
A) Vascular bundles are not arranged in a ring
B) Vascular bundles are arranged in a ring
C) Vascular bundle are radial
D) None of the above

Answer 1

Hint: The membrane is considered as selectively permeable when it allows the movement of water inside the cell or cell organelles. In this process, water from higher concentration passes to lower concentration because of the structure of the cell membrane.

Complete answer:
To answer this question, we have to know about the girdling experiment. The girdling experiment is also named as the ringing experiment. In this experiment the tissue outside of the vascular cambium is being removed that includes bark, phloem, and cortex except xylem. The xylem is the remaining tissue in the girdle’s portion that connects the upper and the lower portion of the plants. This is put in a beaker of water, after some time it is observed that there is swelling in the upper part of the plant and formation of a ring as a result of food material accumulation. After a few days the root of the plant dies as the food transporting tissue that is phloem is not present and with time the plant also dies as the plant depends on the root for ascent of sap. This technique is mostly used for the production of large fruit-bearing plants. The girdling restricts the movement of nutrients to the root and the starch produced by the leaves does not get stored in the root rather it is used by the production of larger fruit.
Now, this ringing experiment is not successful in monocot plants as the vascular bundle found in monocot plants is scattered, this is considered as an atactostele condition. In this condition the xylem and the phloem are arranged randomly therefore, some of the phloem part may remain after girdling and the movement of food materials takes place towards the root.

Hence, the correct option is ‘D’. Vascular bundles are not arranged in a ring.

Note:In the dicot plants the vascular bundles are arranged in a ring form. When the girdling is done the phloem part gets removed and only the xylem will remain as a result of which the ringing experiment shows successful results in dicot plants.