Question

Intrafascicular cambium, Interfascicular cambium and cork cambium constitutes ?

A. Wound meristem

B. Intercalary meristem

C. Lateral meristem 

D. Primary meristem

Answer 1

Hint: Secondary Growth in plants occurs after the first season and results in an increase in thickness and girth of the plants. It is the effect of the activity of the two lateral meristems - the vascular cambium and the cork cambium.

Complete answer:

Intrafascicular cambium, Interfascicular cambium and cork cambium constitute the Primary meristem. Intrafascicular cambium is present in the vascular bundles of dicot stems. It is present between the primary xylem and primary phloem. It is a primary meristem as it is derived from embryonic meristems. It is present in the plant from the very beginning only so it is primary in origin. It produces primary xylem on the inner side and primary phloem on the outer side.

Wound meristem is present along the sides and serves as cork cambium to produce secondary extra Stelar tissues, phelloderm and phellem, which in turn increase the girth of the plant part. Wound meristem production is induced by injuries. It is not produced during normal secondary growth. 

Intercalary meristem is a type of meristematic tissue associated with the growth in length in the middle position. The growth at this point is referred to as intercalary growth. These are capable of cell division, and they allow for rapid growth and regrowth of many monocots. These are made up of meristematic cells that divide mitotically in the stem at the base of nodes and leaf blades.

Lateral Meristem is present on the lateral side of the stem and root of a plant. These meristems help in increasing the thickness of the plants. These are arranged parallel to the sides of an organ and that is responsible for the increase in the diameter of the organ.

Therefore we can say that the correct answer is option (D).

Note: Cambium in plants, a layer of actively dividing cells between xylem (wood) and phloem (bast) tissues that is responsible for the secondary growth of stems and roots. Cambium is important to promote the growth of secondary xylem and phloem. It's located directly between the primary xylem and phloem in a circular layer.