Complex Permanent Tissues

A group of physically diverse cells fulfilling a common function or set of functions is referred to as complex permanent tissue. They are made up of a variety of cell types. They are divided into two categories: xylem and phloem. The xylem is the plant’s primary water-conducting tissue. From the roots to the stems and leaves, it acts as a conducting tissue for water and minerals. Phloem is the plant’s primary food-carrying tissue. It is a living tissue that transports food materials from where they are available to where they are required.

Permanent Tissue Types

Permanent Tissue (Simple)

Homogeneous tissues are another name for this type of tissue. They are made up of a single cell type, which has the same origin, structure, and function in most cases.

Simple permanent tissue is divided into three categories:

Parenchyma

• The cells are oval or circular in form.
• Hemicellulose or cellulose make up the cell wall.
• The cell has a very thin wall.
• Vacuoles and a tiny nucleus are present in the cells.
• It can be found throughout the plant.
• Protoplasm is thick and alive.
• Collenchyma
• Long and thick-walled cells.
• Cellulose and pectin make up the cell wall.
• Due to the presence of pectin, it is the only tissue with the highest refractive index.
• It’s present in the dicot leaf’s epidermis and vascular bundle.
• In the cells, the amount of chloroplast is lower.
• There are no intercellular gaps between the cells.

Sclerenchyma

• These are dead tissues with a stiff and hard feel.
• Cells have sturdy walls and come in a variety of sizes and shapes.
• These give the plant mechanical support and rigidity.
• Tissue that is persistent and complex
• The complex tissues are made up of different types of cells that perform different roles and are divided into two categories:

Tissues of the Laticiferous

Latex is found in plant tissues.

They are derived from meristematic tissues and mature in conjunction with other tissues.

The cells are multinucleated, elongated, and have thin walls.

It can be found in a variety of plant families, including Euphorbiaceae, Apocynaceae, Compositate, and others.

Tissues of the Glandular System . They have glands that secrete oil, resins, tannin, mucilage, and other substances. On the epidermis, the gland is located.

Sclerenchyma Tissue Types:

Sclerenchyma is divided into two types: fibers and sclereids, which are briefly explained below.

Fibers

Fibers are long, elongated cells that can be found in stems, roots, and leaf vascular bundles. Fibers with tapered ends form the bundle caps and sheaths of vascular bundles, which can be several centimeters long in monocotyledonous plants.

They are the longest cells in higher plants. They might be anywhere between 1 and 8 mm in length. Clusters, bunches, and patches are common sightings. They don’t have a nucleus or cytoplasm. Fiber cell walls are uniformly thickened and lignified. The two main types of fibers are intraxylary and extraxylary. Intraxylary fibers are found in the xylem. Extraxylary fibers can be found outside of the xylem in the cortex, pericycle, or phloem.

Sclereids

Fiber cells and stone cells, often known as sclereids, are two forms of sclerenchyma cells.

Sclereids are sclerenchyma cells that differ from fibers in that they are shaped differently. Elongated cells make up fibers. Sclereids are often isodiametric in shape (i.e. roughly spherical or polyhedral). It’s possible that they’re branched. They can be found alone (idioblast) or in small groups. They usually have a shorter length than fibers. They are responsible for the rough texture of pear fruit, for example. They can also be found in layers, such as in hard seed coatings. Secondary phloem contains more sclereids than primary phloem in phloem tissues.

Complex tissue 

Complex permanent tissues are made up of a variety of physically distinct cells that work as a unit to accomplish a variety of complex functions. As a result, complex tissues are made up of cells of many types. Vascular tissues are complex permanent tissues that aid in the transfer of water, nutrients, and organic matter throughout the plant body. Xylem and Phloem are the two most prevalent complex permanent tissues found in plants.

Xylem

It delivers water and nutrients from the plant’s roots to its leaves.

It aids the growth of the plants.

Tracheids, vessels, xylem fibre, and xylem parenchyma are the four divisions.

Phloem

It transports ready-to-eat organic food from the leaves to various areas of the plant.

Bast is another name for it.

Sieve tubes, companion cells, phloem parenchyma, and phloem fibers make up this structure.

Tissues of a Particular Kind

They are of two sorts, both of which have been structurally changed to carry out secretory tasks in nature:

Conclusion

Plants’ parenchyma is a simple permanent tissue found underneath the epidermis. It is made up of live cells that have thin cell walls and are loosely packed to allow for intracellular space. Because parenchyma contains chlorophyll, it participates in photosynthesis. It offers storage capabilities as well as other features. The parenchyma cell wall is made up of cellulose and contains vacuoles and a nucleus.