How Many Types of Meristematic Tissue

Introduction

Meristematic tissues are classified into three types: apical (at the tips), intercalary or basal (in the middle), and lateral (at the sides). Plants have a type of tissue called meristem. It is made up of undifferentiated cells (meristematic cells) that can divide.

Cells in the meristem can differentiate into all of the other tissues and organs found in plants. These cells divide indefinitely until they differentiate and lose the ability to divide. Differentiated plant cells can not divide or produce different types of cells. Meristematic cells are undifferentiated or partially differentiated cells. They are totipotent, meaning they can divide cells indefinitely.

Meristematic cell division generates new cells for tissue expansion and differentiation, as well as the formation of new organs, forming the basic structure of the plant body. The cells are small, with no or few vacuoles and protoplasm filling the entire cell. Plastids are undifferentiated but present in a primitive form. Meristematic cells are tightly packed together with no intercellular spaces. The cell wall is a primary cell wall that is very thin.

Characteristic Features of Meristematic Tissues

• Meristems are the name given to the cells that make up these tissues.

• The ability to regenerate itself exists in meristematic tissue. One cell from each division is similar to the parent cell, while the other cells develop specialised features.

• They contain a very small and less number of vacuoles.

• They are thin-walled meristematic tissue.

• The cells' protoplasm is extremely thick.

• The meristematic tissues are young cells .

• They have a high level of metabolic activity.

• They have a single, large nucleus.

Types of Meristematic Tissues

1. Apical meristems - Apical meristems are the plant’s completely undifferentiated meristems. These are classified into three primary meristems. The two secondary meristem types are produced by the primary meristems. Because they are involved in lateral growth, these secondary meristems are also known as lateral meristems.

Apical meristem tissue is classified into two types: Shoot apical meristem (SAM), which gives rise to organs such as leaves and flowers, and Root apical meristem (RAM), which provides meristematic cells for future root growth.

SAM and RAM cells divide rapidly and are considered indeterminate in the sense that they have no defined end state. In this regard, meristematic cells are frequently compared to animal stem cells, which have similar behaviour and function.

2. Intercalary meristems - Intercalary also known as basal meristems are found at the base of nodes and leaf blades in monocot stems. Intercalary growth is also seen in horsetails and welwitschia. Many monocots use intercalary meristems for rapid growth and regrowth because they are capable of cell division. Intercalary meristems at bamboo nodes promote rapid stem elongation, while those at the base of most grass leaf blades promote rapid leaf regeneration. This leaf regrowth in grasses is involved in response to grazing herbivore damage.

3. Lateral meristems - The lateral meristems of a plant are found on the lateral side of the stem and root. These meristems aid in the thickening of the plants. Lateral meristem tissue is the vascular cambium and the cork cambium.

Conclusion

More dermal, ground and vascular tissue are produced by meristem tissue, as well as more of its tissue and organs. Primary tissue development is carried out by apical meristems. The first cells to divide are those close to the apical meristem. After that, they lengthen and finally become more distinct. Primary meristematic tissue helps the plant grow long or vertically, which means it helps the plant grow upward toward the sun and downward into the earth. Among other things, secondary meristematic tissue supports the girth or lateral growth of a plant's stems, branches, and roots.