Question

A nail is inserted in the trunk of a tree at a height of 1 metre from the ground level. After 3 years the nail will
A. Move downwards
B. Move upwards
C. Remain at the same position
D. Move sideways

Answer 1

When a nail is inserted within the trunk of a tree at a height of 1 metre from the bottom, even after 3 year the nail remains at the same level. It doesn't move upwards because the apical meristem liable for growth (length) is present within the apices only and lateral meristem responsible for increase in girth will cause no change long. The plant grows long by apical meristems. The distribution of apical meristem is on the tip of the root and shoots. A nail is inserted at the permanent tissue of the trunk, that means the part that does not divide.

Complete answer:

Meristematic tissues: These are the tissues that exhibit the capacity to divide. They need a skinny cellulose wall. They do not have intercellular spaces. They contain dense cytoplasm with a prominent nucleus. They contain many small vacuoles in their cytoplasm. They produce permanent tissues. they're liable for the first and secondary growth of the plants.
Permanent tissues: These are the tissues that have lost the tendency of division. They need a thick cellulose wall. They need large intercellular spaces. They contain a skinny cytoplasm with a traditional nucleus. They contain one large vacuole in their cytoplasm. they're produced by meristematic tissues. These tissues increase the varied growths.
Apical meristem, region of cells capable of division and growth within the root and shoot tips in plants. Apical meristems produce to the first plant body and are liable for the extension of the roots and shoots. Unlike most animals, plants still grow throughout their entire lifetime due to the unlimited division of those and other meristems.

So, from the above discussion it can be concluded that the correct answer is option C.

Note:
The tissues that are completely grown and have lost the power of division are referred to as permanent tissues. The meristematic tissues divide and differentiate to make the permanent tissues. Meristematic tissue cells are either undifferentiated or incompletely differentiated; they still divide and contribute to the expansion of the plant. In contrast, permanent tissue consists of plant cells that are not any longer actively dividing. Such cells combat specific roles and lose their ability to divide further.