Question

Grass stem elongates by the activity of __________
A) Apical meristem
B) Intercalary meristem
C) Lateral meristem
D) Primary meristem

Answer 1

Hint:Meristems are the plant tissue composed of meristematic tissue containing undifferentiated, self-renewing stem cells from which various plant parts arise as a result of repeated mitotic divisions.

Complete answer:
Meristems, based on the location in which they exist are divided into three types:
i) Apical meristem- located at the tips.
ii) Intercalary meristem- located in the center.
iii) Lateral meristem- located on the sides.
Now, let us look at each option one by one.
>Apical meristem is present at the tips of the shoots and roots and is responsible for the growth of the roots and shoots pushing the oler tissue behind it. Therefore, this option is incorrect.
>Intercalary meristem is present in the center of the plant and contributes to the elongation of the plant stem, Therefore, this is the correct option.
>Lateral meristem is present at the sides of the plant and is usually responsible for the increase in the girth of the plant. Therefore, this option is incorrect.
>Primary meristem is the meristem responsible for the primary (or initial) growth of the plant. It does not necessarily mean the stem, Therefore, this option is incorrect.

Thus, the correct answer to this question is (B) Intercalary meristem.

Note:As we know, lateral meristem is responsible for the increase in the girth of the plant which forms the basis of the secondary growth in plants. This process usually involves the increase in the size of the cork cambium. In large trees, the increase in girth can be easily observed in the form of rings in the cross-section of the stem and the number of rings observed corresponds to the age of the tree.