Question

Grass stem elongates after initial growth due to
(a) Lateral meristems
(b) Secondary meristems
(c) Intercalary meristem
(d) Apical meristem

Answer 1

Hint: Primary meristem which is present in between the mature tissues helps in replacing the lost cells by grazing herbivores and elongating the stem.

Complete answer:
Meristems are a region of a plant where a rapid division of cells takes place. Two different kinds of meristems are root apical meristem and shoot apical meristem. There are two types of meristems namely primary meristems and secondary meristems. The regenerative parts removed by the herbivores are regenerated by intercalary which is a type of primary meristem.

Additional Information: - In all plants, growth takes place in a specialized region where a rapid division of cells occurs is called meristems.
- Meristems which produce primary tissues at root and shoot tips are called apical meristems. If these meristems present on the shoots they are called shoot apical meristem and if they appear in roots they are called root apical meristem.
- Meristems are of two types: primary meristems and secondary meristems.
- Primary meristem is further divided into two types: intercalary meristem and apical meristem.
- During elongation of the stem and formation of leaves some cells are left behind the apical meristem called as an axillary bud that is present in the axils of leaves and can form a branch of a flower
- Meristem which occurs in between the mature tissues is called intercalary meristem present in grasses to replace the lost cells in the stem and elongate the stem.
- Primary meristems appear early in the plant life and are useful for the development of whole plant body
- Meristems that occur after the maturation of a plant is called secondary meristems or lateral meristem
So, the correct answer is ‘intercalary meristem’

Note: -Secondary meristems are cylindrical which include cork cambium, vascular cambium, interfascicular cambium.
-They help in the secondary growth of the plant.
-Some newly formed cells become functionally stabilized and lose the ability to divide. They are called permanent cells.