Question

If you hammer a nail on the tree trunk at a distance of 2 ft from the base and the tree grows 1 ft every year, at what distance will you find the nail after 10 years?
a. 20 ft
b. 2 ft
c. 25 ft
d. 10 ft

Answer 1

Plants have various tissue levels of organisation; they don't have a typical organised immune or self defence system. Trees grow, due to the division of meristematic cells, which are located in the apical (at root and shoot tips), lateral (in vascular and cork cambia), and intercalary (stem regions between the places where leaves attach and leaf bases).

Complete answer:
- Growth in plants occurs within groups of rapidly dividing cells called meristems.
- Most plants have apical meristems located on the tips of the green shoot and also on the tips of roots below ground.
- New growth always appears at the tips of the branches. The same growth pattern occurs in roots as apical meristems add new cells, making roots longer as they grow into the soil.
- Plants are also able to grow in diameter.
- A young tree might have a small diameter.
- The diameter of the trunk will increase as the tree continues to grow. This is why trees have annual rings showing growth during each year.
- If you hammer a nail on the tree trunk, it will stay at the same height. Only the top of the tree and the root will grow over the years. The tree will grow inside out resulting in the increase in diameter.

Hence, the correct answer is option (B).

Note: Meristem is the region of cells capable of division and growth in plants. Apical meristems produce to the first plant body and are liable for the extension of the roots and shoots. Lateral meristems are known as secondary meristems because they are responsible for secondary growth, or increase in stem girth and thickness.