Tissues

• Plant tissues

  Meristematic plant tissues

  Types

  Apical(present in roots and shoots,provides height)

  Intercalary(present in nodes, primary growth)

  Lateral(increase in grith of stem)

  the cells of these tissues are very active.

  they have dense cytoplasm and lack vacuoles and have thin cellulose walla

  Diff between meristematic and Permanent
• Meristematic cells by the process of differentiation turn into permanent cells.

  A few layers beneath the Epidermis are The simple Permanent tissues

  • Parenchyma
  • Collenchyma
  • Scelrenchyna
• Parenchyma tissue

  • Structure: made up of living cells which are loosely packed with large central vacuole.
  • Location: Present in Cortex and soft parts of the plant
  • Function: Stores food, helps in photosynthesis (chlorenchyma), helps aquatic plants float(Aerenchyma).
• Collenchyma

  • Structure:The cells are living, elongated and irregularly thickened at the corners. They have little intercellular spaces.
  • Location: Underneath the Epidermis
  • Function: Allows bending of plants without breaking and mechanical support.
• Sclerenchyma

  • Structure: formed from Dead cells with thickened, typically lignified, walls. Has no intercellular space
  • Location: Stems around vascular bundles, veins of the leaves and coverings of nuts and seeds.
  • Function: Provide hardness and stiffness' to the plant
• Epidermis

  • Structure: made up of single layers of cells, no intercellular spaces, thick layer of cutin , flat, outer walls and side walls are thicker than inner ones.
  • Location: Outermost layer of the plant
  • Function: Protection against loss of water, Mechanical injury and invasion by bacteria
  • Transpiration and exchange of gases{Stomata/Guard cells}
• Complex Permeant tissues

  Complex permeant tissues are made of more than one type of cells.

  They constitute vascular bundles(made their survival possible)

  • XYLEM
  • PHLOEM
• xylem: the vascular tissue in plants which conducts water and dissolved nutrients upwards from the root.

  it consist of four parts

  • Tracheid(Thick walls, Tubular structure, Transportation)
  • Vessels(Thick walls, Tubular structure, Transportation)
  • Parenchyma(Stores food)
  • Fibers(supportive)
• Phloem: the vascular tissue in plants which conducts sugars and other substances downwards from the leaves. These consist of

  • Sieve cells(living)
  • Sieve tubes( Living tubular cells with perforated walls)
  • Companion cells(living)
  • Fibers(dead)
  • Parenchyma(living)