Plant Tissue
“Plant tissues are groups of cells that perform specific functions in plants.”
What is Plant Tissue?
Plant tissue refers to a group of cells that are structurally and functionally similar. It is categorized into two major types: meristematic tissue and permanent tissue. These tissues work together to help plants grow, develop, and perform essential functions such as transport, storage, and photosynthesis.
Types of Plant Tissue
- Meristematic Tissue: These are tissues that consist of actively dividing cells. They are responsible for plant growth. Meristematic tissues are classified into three types:
- Apical Meristem: Found at the tips of roots and stems, responsible for primary growth.
- Lateral Meristem: Found in the cambium, responsible for secondary growth.
- Intercalary Meristem: Found at internodes or leaf bases, responsible for elongation of stems.
- Permanent Tissue: These tissues consist of cells that have differentiated and specialized for specific functions. Permanent tissues are of two types:
- Simple Permanent Tissue: Made up of one type of cell and performs simple functions. Examples include parenchyma, collenchyma, and sclerenchyma.
- Complex Permanent Tissue: Consists of more than one type of cell, performing complex functions. Examples include xylem and phloem.
Meristematic Tissue
Meristematic tissues are found in regions of the plant where growth is occurring. These tissues contain undifferentiated cells that can divide and form new cells. Meristematic tissue is classified based on its location and function:
- Apical Meristem: Located at the growing tips of roots and stems, responsible for increasing the length of the plant.
- Lateral Meristem: Found in the cambium and cork cambium, responsible for secondary growth, which increases the thickness of the plant.
- Intercalary Meristem: Located at the base of leaves or internodes, responsible for the elongation of stems and leaves.
Permanent Tissue
Permanent tissues are formed when meristematic cells differentiate into specialized cells. These tissues can be simple or complex, depending on the variety of cells they contain.
Simple Permanent Tissue
- Parenchyma: These are thin-walled, living cells that perform various functions such as storage and photosynthesis.
- Collenchyma: These cells have unevenly thickened walls and provide flexible support to growing parts of plants, like young stems and petioles.
- Sclerenchyma: These are thick-walled, dead cells that provide mechanical strength to the plant. They include fibers and sclereids.
Complex Permanent Tissue
- Xylem: A tissue responsible for the transport of water and minerals from roots to other parts of the plant. Xylem consists of tracheids, vessel elements, xylem parenchyma, and xylem fibers.
- Phloem: A tissue responsible for transporting food (mainly sugars) from leaves to other parts of the plant. Phloem consists of sieve tube elements, companion cells, phloem parenchyma, and phloem fibers.
Functions of Plant Tissues
Plant tissues are specialized to perform different functions:
- Meristematic Tissue: Involved in growth and development, helping plants grow in size.
- Parenchyma: Responsible for storage, photosynthesis, and gas exchange.
- Collenchyma: Provides flexible support to growing parts of the plant.
- Sclerenchyma: Provides structural support and rigidity to the plant.
- Xylem: Transports water and nutrients upward from the roots to other parts of the plant.
- Phloem: Transports food from the leaves to other parts of the plant.
Importance of Plant Tissue
Understanding plant tissues is essential for fields like agriculture, horticulture, and forestry. It helps in improving plant breeding, increasing crop yield, and developing plant-based products. The knowledge of how plants grow and function at the tissue level is crucial for the sustainable management of plant resources.
Previous Year Questions
- RRB JE 2019: Which of the following is responsible for the transportation of water in plants?
- Option A: Xylem
- Option B: Phloem
- Option C: Parenchyma
- Option D: Collenchyma
- Option A: Xylem
- SSC JE 2018: What type of meristematic tissue is responsible for the increase in the thickness of stems?
- Option A: Apical meristem
- Option B: Lateral meristem
- Option C: Intercalary meristem
- Option D: Vascular cambium
- Option B: Lateral meristem
- HSSC CET 2020: Which tissue in plants is responsible for food conduction?
- Option A: Xylem
- Option B: Phloem
- Option C: Sclerenchyma
- Option D: Parenchyma
- Option B: Phloem