Apical Meristem

Meristem

In plants, a meristem is a form of tissue. It is made up of undifferentiated cells (meristematic cells) that can divide. The meristem's cells will grow into some of the plant's other tissues and organs. These cells divide until they become differentiated, at which point they lose their ability to divide. Apical (tips), intercalary (middle), and lateral meristematic tissues are the three types of meristematic tissues (at the sides). The central region, a small group of slowly dividing cells at the meristem summit, is generally referred to as the meristem summit.

Apex in Plants  

The rising terminal portions of the stem and roots in plants are known as the apex. The apical portion of the stem is known as 'Shoot Apex,' while the apical portion of the root is known as 'Root Apex.' The 'Apical Meristem' is a meristematic tissue found at the apex of both the stem and the base.

Apex meaning in biology is referred to as the rising terminal portions of the stem and roots in plants are known as the apex. The apical portion of the stem is known as 'Shoot Apex,' while the apical portion of the root is known as 'Root Apex.' The 'Apical Meristem' is a meristematic tissue located at the tip of both the stem and the base.

What is Apical Meristematic Tissue?

The apical meristematic tissue is a tissue found in the plant which is responsible for plant growth and found in the root tips as well as the tips of new shoots and leaves. One of three types of meristems, or tissue that can divide into various cell types, is the apical meristem. In plants, the meristem is the tissue where development takes place. Apical growth refers to growth that occurs at the plant's top and bottom tips. Apical meristems give rise to the primary plant body and are in charge of root and shoot extension.

Apical Meristem Structure

The apical meristem is found in the roots just below the root cap. The apical meristem is a tightly packed cluster of undifferentiated cells. Many of the plant's different cell structures are derived from these cells. Undifferentiated apical meristem cells divide repeatedly, eventually transforming into specialized cells. Cells are formed in two directions in the root apical meristem. 

Cells in the shoot apical meristem only develop in one direction. The shoot apical meristem can be found at the tips of plants, as in many dicots, or it can start slightly below the soil and produce upward-growing leaves, as in most monocots. The shoot apical meristem, however, is the growing core of all above-ground growth in both classes.

Types of Apical Meristem  

The apical meristem, which is located just beneath the surface of the branches and roots furthest from the plant's heart, is constantly dividing. Other cells divide and differentiate into structural or vascular cells, while some cells divide and differentiate into more meristematic cells. Most plants have two apical meristem sites. 

  • Root Apical Meristem:

The root apical meristem creates cells in two dimensions, unlike the shoot apical meristem. It contains two pools of stem cells that cluster around an organizing core known as the quiescent centre (QC) cells and generate the majority of the cells in an adult root. The root meristem is protected and guided along its growth path by the root cap, which is located at its apex. The root cap's outer surface is continually sloughed off with cells. The low mitotic behaviour of QC cells distinguishes them. In the case of primary roots, the apical meristem and tissue patterns are formed in the embryo, while in the case of secondary roots, they are established in the new lateral root primordium.

  • Shoot Apical Meristem:

Plants have a shoot apical meristem at their tips. This apical meristem is in charge of producing cells and growing to propel the plant into the light and air, where it can photosynthesize and exchange gases. The root apical meristem is located at the root's tip. 

Signals are produced within the apical meristem in response to the conditions of the soil around the root, directing the plant towards the water and desired nutrients. As a result, roots often enter pipes for water and drainage, which also hold many of the nutrients they need. Even as the root cap is scraped away as it pushes through the soil, the apical meristem, which is covered by the root cap, continues to grow cells. The apical meristem must produce enough cells to expand into the soil as well as replace cells lost to abrasion.

Define Apical Membrane

The apical (inner or upper) surface of transporting epithelial cells is referred to as the apical membrane. In vertebrates, a ring of close junctions separates this portion of the apical membrane from the basolateral membrane, preventing the free mixing of membrane proteins from these two domains. The apical membrane faces the exterior of the organ.

FAQs (Frequently Asked Questions)

Q1. Explain different Types of Meristem.

Ans. There are three types of meristematic tissues which are found in plants. Apical meristematic tissues(tips), intercalary meristematic tissues (middle), and lateral meristematic tissues are the three types of meristematic tissues (at the sides). The central region, a small group of slowly dividing cells at the meristem summit, is generally referred to as the meristem summit. 


Various cell divisions aid cellular enlargement and promote cell growth in the roots and shoots. The meristematic zone, which contains protoderm, procambium, and ground meristem, is divided into two zones: the promeristem zone, which contains actively dividing cells, and the meristematic zone, which contains protoderm, procambium, and ground meristem.

Q2. Do All Plants have an Apical Meristem?

Ans. Yes, all plants have apical meristematic tissues which play an essential role. Cell divisions in the apical meristems lead to cell expansion and differentiation, which results in the formation of all plant organs. The apical part of many plants is formed by primary development. Apical meristems are found at the tip (or apex) of the shoot, root, and branch tips. All plants have these meristems, which are responsible for length growth. The apical meristem is a plant growth area found in the root tips as well as the tips of new shoots and leaves.