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The plant tissue system includes permanent and meristematic tissues, each with distinct roles. The plant tissue system diagram shows that it is composed of three main tissue types: dermal, vascular, and ground tissues. Studying the plant tissue system and its functions helps us understand how plants grow, transport nutrients, and adapt to their environments.
In this article, we will cover the plant tissue system and their classification, examples, and diagram.
What is Plant Tissue?
Plant tissue are organized into systems such as dermal, vascular, and ground tissues. Dermal tissues form the outer protective layer of the plant, while vascular tissues facilitate the transport of water, nutrients, and sugars. Ground tissues fill the interior of the plant and perform various metabolic functions, including support and storage. Plant tissues can be further categorized into permanent tissues, which are mature and differentiated, and meristematic tissues, which are regions of actively dividing cells responsible for growth and development.
Classification of Plant Tissue System
Classification of plant tissues based on location and the kind of cells they contain is given below:
Classification of Plant Tissues Based on Location in the Plant
Classification of Plant Tissues Based on Location in the Plant is given below:
- Epidermal Tissues
- Location: Covers the outside of a plant in a single layer of cells.
- Function: Protects against water loss, pathogens, and physical damage.
- Ground Tissues
- Location: Fills the interior of a plant.
- Function: Provides support, storage, and is involved in photosynthesis.
- Vascular Tissues
- Location: Found throughout the plant, primarily in the roots, stems, and leaves.
- Function: Transports water, nutrients, and organic compounds.
Classification of Plant Tissues Based on the Kind of Cells They Contain
Classification of Plant Tissues Based on the Kind of Cells They Contain is given below:
- Meristematic Tissues
- Characteristics: Composed of actively dividing cells.
- Types:
- Apical Meristems: Located at the tips of roots and shoots, responsible for primary growth.
- Lateral Meristems: Found in stems and roots, responsible for secondary growth (increase in girth).
- Intercalary Meristems: Located at internodes or the base of leaves, particularly in monocots, facilitating growth in length.
- Permanent Tissues
Types of Plant Tissues
Plant Tissues, based on their physical structure and functionality, can be grouped into- meristematic, permanent, and protective tissues.
- Meristematic Tissues
- Permanent Tissues
- Protective Tissues
Meristematic Tissues
These cells undergo continuous division, contributing to the increase in both- the length and girth of the plant. Upon maturation, these tissues have the ability to stretch, elongate, and differentiate into other types of tissues. Meristematic tissues can be categorized into three types: apical meristems, lateral meristems, and intercalary meristems.
- Apical Meristem: These tissues are found at the tips of shoots and roots, which help in the increase of plant length.
- Lateral Meristem: These tissues are found at the radial fractions or a root. This meristem helps in the structural development of the plant.
- Intercalary Meristem: These tissues are located at certain points along the stems or internodes of plants. These meristems play an important role in plant growth and development, contributing to the lengthening and branching of the plant.
Permanent Tissues
These tissues are also known as non-meristematic tissues, consisting of cells that have undergone differentiation and have attained a permanent form and function. There are three kinds of simple permanent tissues – parenchyma, collenchyma, and sclerenchyma.
- Parenchyma: These consist of living cells polygonal in shape with a large vacuole in the center. The parenchyma tissues perform the following functions including storage, photosynthesis, and buoyancy (flotation of plant on water). Additionally, they have large intercellular spaces in between them.
- Collenchyma: These tissues consist of living cells and elongated in shape, and have no intercellular space between them. These provide mechanical support and flexibility; they allow different parts of the plant easy-bending properties.
- Sclerenchyma: This tissue is made up of dead cells that have lignin deposits on their cell wall. These provide the plant with mechanical strength thus aiding the plant to survive severe strains.
Complex Permanent Tissues
These tissues are made up of a combination of cell types. These cells work together to perform specialized functions. There are two types of complex tissues- xylem and phloem.
- Xylem: This tissue is vascular & mechanical in form. Its primary function is the transportation of water and minerals upwards from the roots to other parts of the plant also, the xylem functions in only one direction i.e. vertical. Its secondary function is to provide structural support. The xylem is composed of four components- tracheid, vessels, xylem parenchyma, and xylem fibers.
- Phloem: Unlike the xylem, the phloem is bidirectional i.e. it can function upwards as well as downwards. Phloem transports the food prepared via photosynthesis from the leaves to the whole plant body.
Protective Tissues
These tissues offer support to a plant. These are mainly of two types: cork and epidermis.
- Cork: This tissue is made up of dead cells and acts as an outer protective layer of the plant. Additionally, this tissue lacks intercellular gaps and is therefore impenetrable to gas and water molecules.
- Epidermis: Present in the outermost layer of the plant i.e. on flowers, roots, stem, etc., this layer protects the plant from physical damage. Epidermis tissues are covered with cuticle, a waxy, water-proof substance secreted by epidermal cells. Cuticle helps reduce evaporation of water from the plant and entry of pathogens thus protecting the plant from desiccation & infection.
Properties of Meristematic Tissues
Properties of Meristematic Tissues are:
- Meristematic tissues consist of cells that are actively dividing, contributing to plant growth and development.
- Cells in meristematic tissues are undifferentiated and have the potential to differentiate into various specialized cell types.
- Meristematic tissues are primarily located in regions of the plant where growth occurs, such as the tips of roots and shoots.
- These tissues enable rapid growth and elongation of plant structures, allowing for the formation of new roots, stems, leaves, and reproductive organs.
- Meristematic cells are pluripotent, meaning they have the ability to develop into different types of cells depending on environmental cues and developmental signals.
- Cells in meristematic tissues are generally small and densely packed, with thin cell walls and abundant cytoplasm to support active cell division.
- Meristematic tissues lack specialized structures such as chloroplasts and vacuoles, as their primary function is cell division rather than specialized metabolic activities.
Properties of Permanent Tissues
Properties of Permanent Tissues are:
- Permanent tissues consist of mature, specialized cells that have ceased to divide and have adopted specific functions.
- Permanent tissues comprise various cell types adapted to perform specific functions such as support, storage, and photosynthesis.
- Some permanent tissues, like sclerenchyma and collenchyma, provide structural support to plant organs, aiding in upright growth and resistance to mechanical stress.
- Parenchyma cells, a type of permanent tissue, are involved in essential metabolic processes such as photosynthesis, respiration, and storage of nutrients.
- Permanent tissues exhibit adaptations to environmental conditions and plant requirements, such as the ability to store water or withstand mechanical forces.
- Permanent tissues are distributed throughout the plant body, serving specific functions in different organs and tissues.
- Cells in permanent tissues have stable cell walls and structures suited to their specialized functions, allowing for long-term maintenance and integrity of plant tissues.
Vascular Cambium
The vascular cambium is a meristematic tissue layer found in the stems and roots of many vascular plants, and is responsible for secondary growth or increase in girth. It is generally located between the xylem and phloem in the stem and vascular bundles of the root. The primary function of the vascular cambium is to produce secondary xylem (wood) and secondary phloem (inner bark), thereby contributing to secondary growth. In addition to the vascular cambium, several plants have a cork cambium (phellogen) that produces cork cells towards the exterior, forming the protective outer bark layer.
Plant Tissue System and Their Functions
Plant tissue system function includes:
- Provides a protective barrier against physical damage, pathogens, and water loss.
- Facilitates the movement of water, nutrients, and sugars throughout the plant.
- Provides structural support to maintain the plant’s shape and enable upright growth.
- Conducts photosynthesis to produce energy and organic compounds necessary for growth and development.
- Stores nutrients, water, and energy reserves in various plant parts.
- Enables growth through cell division and differentiation, and assists in tissue repair and regeneration.
- Regulates the exchange of gases (oxygen, carbon dioxide) necessary for photosynthesis and respiration.
- Produces compounds and structures (e.g., trichomes, secondary metabolites) that deter herbivores and pathogens.
- Supports the development of reproductive structures such as flowers, fruits, and seeds.
Conclusion – Plant Tissue System
In conclusion, the plant tissue system is essential for the growth, development, and overall functionality of plants. It comprises meristematic tissues, which drive growth through active cell division, and permanent tissues, which perform specialized roles such as protection, transport, support, and storage. The organization of dermal, vascular, and ground tissues ensures efficient functioning and adaptability to various environmental conditions. These systems collectively enable plants to thrive and sustain themselves in diverse ecosystems.
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FAQs on Plant Tissue System
In which parts of the Plant are Parenchyma, Collenchyma, and Sclerenchyma present?
Parenchyma cells are distributed throughout the plant, including the roots, stems, leaves, fruits. Collenchyma cells are located in the stems and leaves. Sclerenchyma cells are present in plant parts, such as the stems, roots, leaves.
What is the Difference between Collenchyma and Sclerenchyma?
Sclerenchyma cells have a thick, rigid secondary cell wall which is absent in collenchyma, and collenchyma cells are relatively flexible and can elongate as the plant grows while sclerenchyma cells are rigid and lack flexibility .
What are Some Different Kinds of Plant Tissues?
Some different kinds of plant tissues include meristematic, dermal, vascular, and ground tissues.
Can we Distinguish Between Meristematic and Permanent Tissues?
Yes, meristematic tissues consist of actively dividing, undifferentiated cells responsible for growth, while permanent tissues comprise mature, differentiated cells specialized for specific functions.
Where are Meristematic Tissues found?
Meristematic Tissue is present at all growth points, including the tips of roots, stems, and branches. Its function is to generate new cells that aid in the expansion of the plant’s body.
Dead tissues in plants provide support and protection. For example, the dead cells in the outer bark of trees, like cork cells, act as a protective barrier against physical damage, pathogens, and water loss.
How can we Classify Plant Tissues?
Plant tissues can be classified into meristematic tissues, which are involved in growth, and permanent tissues, which include dermal, vascular, and ground tissues.
What is the Plant Tissue?
Plant tissue refers to a group of similar cells that work together and contribute to a plant’s growth, development, support, and protection.
Who Discovered Tissue?
Xavier Bichata, a French anatomist and pathologist, discovered tissues in 1801. He suggested that tissues play a crucial role in human anatomy, determining that organs are essentially comprised of various distinct tissues.
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