Plant Tissues and Meristem

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Questions and Answers

What is the primary function of nectaries in plants?

To secrete nectar (correct)

To excrete latex

To secrete excess water

To store tannins and oils

Which of the following types of tissues is classified as complex?

Collenchyma tissues

Sclerenchyma tissues

Phloem (correct)

Parenchyma tissues

Which of the following secretory cells is responsible for the secretion of digestive enzymes?

Idioblasts

Glandular trichomes (correct)

Nectaries

Hydathodes

What type of tissue are vascular tissues considered to be?

Complex and permanent Signup and view all the answers

Which type of secretory cell is involved in storing essential oils?

Glandular trichomes Signup and view all the answers

What is the role of meristematic cells in plants?

Development of new tissues Signup and view all the answers

Which tissue type provides structural support and elasticity for growing areas of a plant?

Collenchyma tissue Signup and view all the answers

What is the primary function of xylem in vascular plants?

Transport of water and minerals Signup and view all the answers

Which type of plant does not have flowers, seeds, or fruits?

Ferns Signup and view all the answers

What is the function of guard cells in the stomata?

Regulating gas exchange Signup and view all the answers

Where are intercalary meristems located in plants?

Along the internodes of stems Signup and view all the answers

Which cell type in xylem is responsible for fast transport of water?

Vessel elements Signup and view all the answers

What structure is formed by the cork cambium in the periderm?

Cork (Phellem) Signup and view all the answers

Which type of sclerenchyma cells are found in the shells of nuts?

Sclereids Signup and view all the answers

What is the primary role of phloem in vascular plants?

Transporting sugars Signup and view all the answers

Which plant tissue is essential for photosynthesis and tissue repair?

Parenchyma Signup and view all the answers

How do trichomes benefit plants?

Protect against herbivores and reduce water loss Signup and view all the answers

What defines the function of dermal tissue in plants?

Protection from the external environment Signup and view all the answers

Which part of the plant is primarily associated with secondary growth?

Lateral meristems Signup and view all the answers

Study Notes

Plant Tissues

Simple plants are nonvascular and grow in moist environments
- Examples include mosses, liverworts, and green algae.
- They lack vascular systems and tissues.
Vascular plants have three main parts: roots, stems, and leaves
- Examples include trees and grasses.
Ferns are thought to be the first vascular plants to evolve.
- They contain a cuticle.
- They do not have pollen, seeds, flowers, or fruits.
- Ferns reproduce using spores.
Gymnosperms are seed-bearing plants, also known as naked seeds.
- They do not have flowers or fruits.

Meristem

Meristematic tissues are found in regions of plant growth and contain undifferentiated cells.
- These cells do not have specific functions and are responsible for new tissue development and plant growth.
Types of meristems:
- Apical: Located at the growing tip of the shoot and root systems.
  - Root apical meristems are responsible for root growth.
  - Shoot apical meristems are responsible for shoot growth.
  - Contain protoderm (develops into dermal tissues), procambium (develops into primary vascular tissues), and ground meristems (develops into ground tissues).
- Lateral: Responsible for secondary growth (increasing plant girth).
  - Contain vascular cambium (develops into secondary vascular tissue) and cork cambium (develops into periderm).
- Intercalary: Located at intervals along stems (internodes).
  - Promotes stem length and increases plant height

Ground Tissue

Ground tissue is a permanent tissue that makes up most of the plant's structure.
- It consists of:
  - Parenchyma tissue:
    - Consists of parenchyma cells (homogenous).
    - Responsible for tissue repair, photosynthesis, and storage.
    - Thin-walled.
    - Have intercellular air spaces.
    - Can be oval or rectangular in shape.
    - Found in leaves, stems, and roots.
  - Collenchyma tissue:
    - Consists of collenchyma cells (homogenous).
    - Provides structural support and elasticity for the plant, especially in growing areas.
    - Elongated, thick cells.
    - Can be spherical or elongated in shape.
    - Found in stems, leaves, and branches.
  - Sclerenchyma tissue:
    - Consists of sclerenchyma cells (homogenous).
    - Provides structural support and protection.
    - Thick, lignified walls.
    - Irregular or branched in shape.
    - Has two types:
      - Fibers: Long, tapered cells, found in wood, inner bark, and leaf veins of flowering plants.
      - Sclereids: Short cells, found in the shells of nuts and stone fruits.

Dermal Tissue

Dermal tissue is the outer protective layer of the plant.
- It consists of:
  - Periderm:
    - Replaces epidermis at maturity.
    - Protects the plant from the outside environment.
    - Consists of cork (phellem), cork cambium (phellogen), and phelloderm.
      - Cork: Outermost layer, provides protection, is impermeable to water and gases.
      - Cork Cambium: Located below the cork, produces new cork cells and phelloderm cells for secondary growth.
      - Phelloderm: Innermost layer, located beneath the cork cambium, assists in storage of food and water and is made of parenchyma cells.
  - Cuticle:
    - Waxy, hydrophobic layer covering the epidermis.
    - Prevents water loss.
    - Does not have any organelles.
    - Provides a protective layer.
  - Trichomes:
    - Hair-like structures found on the plant's skin.
    - Two types with specific functions:
      - Glandular trichomes: Secrete oil.
      - Non-glandular trichomes: Do not secrete oil.
  - Stomata:
    - Important for photosynthesis, respiration, and transpiration.
    - Consist of:
      - Stomatal pore: Opening part of the stomata for gas exchange and transpiration.
      - Guard cells: Specialized cells that control the opening and closing of the stoma.
      - Epidermal cells: Surround the stoma.

Vascular Tissue

Vascular tissue is found in vascular plants and is embedded within ground tissue.
- It transports nutrients, minerals, and water throughout the plant.
- It consists of:
  - Xylem:
    - Elongated cells.
    - Large lumen.
    - Dead at maturity, no protoplasm.
    - Thickened with lignin (a strong polymer) giving xylem its strength.
    - Transports water and minerals in one direction.
    - Provides structural support.
    - Two types of water-conducting cells:
      - Vessel elements: Short, wide cells for fast transport.
      - Tracheids: Long, narrow cells for transport between cells.
  - Phloem:
    - Contains sieve tube elements for transporting sugars throughout the plant.
    - Two-way movement for sugar distribution.
    - Have companion cells (living cells) that provide nutrients for the phloem and maintain pressure gradients.

Secretory Cells and Tissues

Secretory cells and tissues are involved in the production and storage of substances.
- External secretory structures release secretions and include:
  - Nectaries: Secretes nectar (found in flowers).
  - Hydathodes: Secretes excess water (found in leaves).
  - Glandular trichomes: Secretes oils or digestive enzymes for protection.
  - Laticifers: Secretes Latex.
- Internal secretory structures store secretions and include:
  - Idioblasts: Stores tannins, oils, and calcium oxalate crystals for defense.
  - Glandular trichomes: Contain internal secretory cells that store essential oils.
  - Oil cells: Stores oils.

Important Terms

Simple tissues: Composed of only one kind of cell (homogenous).
- Examples: Parenchyma, collenchyma, and sclerenchyma tissues.
Complex tissues: Have two or more kinds of cells (heterogeneous).
- Examples: Xylem and phloem.
Permanent tissues:
- Derived from meristematic tissues and have specific functions.
- Fully grown tissues.
- Examples:
  - Dermal tissues: Epidermis.
  - Ground tissues: Parenchyma, collenchyma, and sclerenchyma tissues.
  - Vascular tissues: Primary and secondary xylem, primary and secondary phloem.
  - Vascular cambium: Secondary vascular tissues.
  - Vascular cylinder: Primary vascular tissues.

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Description

Explore the fascinating world of plant tissues and meristems with this quiz. Learn about simple and vascular plants, as well as their reproductive methods. Test your knowledge on types of meristematic tissues and their functions.