Question

Explain the different types of meristems based on their positions.

Answer 1

The meristem is divided into three types on the basis of the positions - apical meristem, intercalary meristem and lateral meristem.

(i) Apical meristem is found at the tips of roots, stem and branches. It is responsible for the increase in the length of the plant. It is divided into three zones-protoderm, procambium and ground meristem. Protoderm gives rise to epidermal tissue, procambium gives rise to primary vascular tissues and ground meristem gives rise to cortex and pith.

(ii) Intercalary meristem is present in the nodal region and is prominently found in monocotyledons, e.g grasses. As the name indicates, it is present in between the permanent tissues. It is derived from the apical meristem and is responsible for the elongation of internodes.

(iii) The meristem that is present along the longitudinal axis of stem and root is called lateral meristem. Vascular cambium and cork cambium are examples for lateral meristem. It produces secondary permanent tissues which result in the thickening of stem and root.