Question

A nail is driven into the trunk of a 30 years old tree at a point 1 meter above the soil level. The tree grows in height at the rate of 0.5 metres a year. After three years, the nail will be

• A. 1 meter above the soil
• B. 1.5 meter above the soil
• C. 2 meters. above the soil
• D. 2.5 meters above the soil

Answer 1

Answer: (A)

1 meter above the soil

A 30-year-old tree must have more height than a meter. If a nail is driven at 1 meter above the soil then after 3 years the nail will be at the same height of 1 meter. Though plant is growing at the rate of 0.5 meters a year, this growth occurs at the apex of the plant. The plant growth is carried out by meristematic tissue. At the trunk region, the height does not increase as a nail is inserted in tree trunk, at that point where permanent growth occurs.

Thus, the correct answer is option A.