Question

Promeristem gives rise to which meristem?
(a) Secondary
(b) Lateral
(c) Primary
(d) None of the above

Answer 1

Hint: The meristem rising from promeristem is of two types and responsible for elongation of the plant mainly. Their help is the formation of the main plant body. All other meristems originate from this and it does not contribute to secondary growth.

Complete answer
The promeristem is also known as primordial meristem. IT is considered as the embryonic stage for other developing meristematic tissue. The promeristem gives rise to primary meristem. This meristem is located at the root and shoots tips and in different appendages. The two types of primary meristem are apical and intercalary meristem.

Additional Information:
The classification of meristem can be done on several bases:
1) Classification of meristem based on origin and development:

I. Promeristem or Primordial meristem

II. Primary meristem

III. Secondary meristem

2) Classification of meristem based on the plane of division:

I. Mass meristem: Division of meristem occurs in all planes.

II. Plate meristem: Division occurs in anticlinal fashion in two planes and plate-like structures are formed.

III. Rib meristem: Division of meristem occurs at right angles to the longitudinal axis.

3) Classification of meristem based on position:

I. Apical meristem

II. Lateral meristem: It is of two types marginal lateral meristem and intrafascicular cambium.

III. Intercalary meristem

4) Based on functions Habertland introduced three types of meristem:

I. Protoderm: This layer forms the epidermis.

II. Procambium: Consists of vertically elongated cells. They help in the formation of primary vascular tissue including xylem and phloem.

III. Ground Tissue: Consists of thin-walled, large, and isodiametric cells. It gives rise to the hypodermis, cortex, endodermis, pericycle, medullary rays, and pith.

So, the correct answer is,” promeristem gives rise to primary meristem.”

Note: It should be remembered that the apical meristem also has two regions at the embryonic stage.Primordial meristem which develops during the embryonic stage and meristem which develops from the primordial meristem. Foster further divided meristems based on the rate of cell division into two regions, summit and flank. The secondary meristem develops after the dedifferentiation of permanent tissue.