Plant tissues

The branch of biology that deals with the internal structure and parts of an organism is called "Anatomy". Plant anatomy deals with the internal tissues and cells present in a plant.

A tissue in plants is a cluster of cells that have a common origin and work together to achieve a specific function. A plant tissue varies from that of an animal because they vary in their functions and characters. In plants, there are two types of tissues, namely, Meristematic and permanent tissues. Simple permanent tissues comprise of sclerenchyma, collenchyma, parenchyma, and epidermis.

Meristematic tissues are quite small which allows large number of cell division. Their cytoplasm is quite dense which means that they contain many cell organelles that help them increase their rate of respiration. Their cell wall is thin which allows them to divide easily. However, vacuoles are absent in Meristematic tissues as they interfere with cell division and differentiation. They also provide little to no mechanical support.

Primary meristem rises at the early stage of a plant and comprises of apical and intercalary meristem. Secondary meristem rises at the later stage of a plant and comprises of lateral meristem. Apical meristem is present at tips of root and shoot and also helps in the increase of length. Intercalary meristem is found at the base of the internodes in certain plants and is responsible for the growth in length between the nodes, but it does not contribute to the increase in girth or diameter of the stem.

Permanent cells are formed from the meristem tissues that gradually lose their ability to divide and perform few other specific functions. The process by which meristem tissues gradually change to permanent tissues is called differentiation. Permanent tissues are classified into simple and complex permanent tissues. Simple permanent tissues and complex permanent tissues are classified based on their structural complexity, not their intercellular gaps.

Meristematic tissue is composed of cells that are undifferentiated or incompletely differentiated and continue to divide, contributing to the growth of the plant.

Intercalary meristem occurs only in monocots, at the bases of leaf blades and at nodes. This tissue enables the monocot leaf blade to increase in length from the leaf base.

Ground tissue serves as a site for photosynthesis, provides a supporting matrix for the vascular tissue, and helps to store water and sugars.

Vascular tissue transports water, minerals, and sugars to different parts of the plant.

Dermal tissue covers and protects the plant.

The process by which meristematic tissues gradually change to permanent tissues is called differentiation.

Meristematic tissue cells are undifferentiated or incompletely differentiated and continue to divide and contribute to the growth of the plant. Meristematic tissue cells can differentiate into different types of meristematic tissue, but not into dermal, vascular, and ground tissue. These tissue types are formed from the cells that quickly differentiate from the meristematic tissue.

Intercalary meristems are found only in monocots, which are a type of flowering plant. They occur at the bases of leaf blades and at nodes and allow the monocot leaf blade to increase in length from the leaf base.

Ground tissue provides a supporting matrix for the vascular tissue, which transports water, minerals, and sugars to different parts of the plant. Ground tissue also serves as a site for photosynthesis and helps to store water and sugars.

Ground tissue is a simple tissue, meaning that each ground tissue consists of only one cell type. In contrast, dermal and vascular tissues are complex tissues because they consist of multiple cell types.

Dermal tissue covers the plant and can be found on the outer layer of roots, stems, and leaves. Its main functions are transpiration, gas exchange, and defense.

The epidermis is an example of dermal tissue. It is composed of a single layer of epidermis cells and may contain stomata and guard cells that allow gas exchange, root hairs that increase surface area, or trichomes used in transpiration or defense. It may also contain a waxy cuticle if found on the upper surface of leaves to aid in lowering transpiration.

Stomata are openings in the epidermis that allow plants to take up carbon dioxide and release oxygen and water vapor.

Guard cells are specialized cells that flank each stoma and regulate its opening and closing.

In woody plants, the epidermis breaks apart into a thick periderm as secondary growth allows the plant to grow in girth. The periderm functions as the first line of defense for the plant, protecting it from fire or heat injury, dehydration, freezing conditions, and/or disease.

The periderm is formed as a result of secondary growth in woody plants and includes the cork cambium, cork cells, and phelloderm. The periderm functions as the first line of defense for the plant, protecting it from fire or heat injury, dehydration, freezing conditions, and/or disease.

The periderm functions as the first line of defense for the plant, protecting it from fire or heat injury, dehydration, freezing conditions, and/or disease.

Stomata are not composed of a single layer of epidermis cells; rather, they are openings that penetrate the epidermis and allow gas exchange.

Meristem cells are not a component of the periderm in woody plants. The cork cambium, cork cells, and phelloderm together make up the periderm.

The main function of dermal tissue in plants is to cover the plant and allow for transpiration, gas exchange, and defense.

Ground tissue is not considered dermal or vascular tissue, but rather serves to store molecules, photosynthesize, or support the plant.

The main function of collenchyma is to provide mechanical support to young stems and leaves via turgor.

Sclerenchyma is a dead supportive tissue that consists of long sclerenchyma fibers or short, crystal-like cells.

Sclerenchyma does not photosynthesize. Its main functions include supporting older plant organs, hardening different parts of plants, and making fruit inedible before ripeness.

Parenchyma cells are totipotent, meaning they are capable of differentiating into any cell type.

Sclerenchyma cells have a uniformly thick secondary cell wall rich in lignin, not a primary cell wall. Sclerenchyma is a dead supportive tissue consisting of long fibers or short, crystal-like cells. It provides support to older plant organs and hardens different parts of plants, such as making fruit inedible before ripeness so that no one takes the fruit before seeds are ready to be distributed.

Collenchyma is the type of ground tissue that has elongated cells with an unevenly thickened primary cell wall. Its main function is the mechanical support of young stems and leaves via turgor.

Sclerenchyma is a dead supportive tissue that consists of long sclerenchyma fibers or short, crystal-like cells called sclereids. Its main function is to support older plant organs and harden different parts of plants, such as making fruit inedible before ripeness so no one will take the fruit before seeds are ready to be distributed.

Sclerenchyma fibers occur in groups or bundles. They have a uniformly thick secondary wall that is rich in lignin, and their main function is the support of older plant organs.

Parenchyma cells are totipotent, meaning they are capable of differentiating into any cell type. Their main functions are photosynthesis and storage, and they are a main component of young plant organs.

The process by which cells differentiate into specialized cells is called differentiation.

The primary function of stem cells is to maintain and repair tissues.

Totipotent stem cells can differentiate into any cell type, including embryonic and extraembryonic cells.

Meristem tissues are responsible for producing specialized cells that contribute to plant growth and development.

Vascular tissue, which includes xylem and phloem, is responsible for transporting water and nutrients throughout a plant.

Sclerenchyma cells provide support and structure to plant tissues.