4th Quarter - Periodic (Biology)

• The Plant Body consists of the Shoot System and the Root System
• Tissue – a group of cells that are similar in structure and organization and work together to perform a particular function
• Plant tissues are specialized for functions: absorption, transport, storage, photosynthesis, and reproduction
• A tissue is an organization of cells that work together as a functional unit
• A tissue is an organization of cells that work together as a functional unit
• Xylem and phloem are complex tissues; they are composed of a number of different cell types
• There are three plant tissue systems: vascular, dermal, and ground
• Dermal Tissue  - Outer covering or “skin” of the plant
• Vascular Tissue - Transports water, mineral nutrients, and organic molecules between roots and shoots (ex. Xylem and phloem)
• Ground Tissue - Tissue in between dermal and vascular tissue that functions in photosynthesis, storage, and support
• Xylem - Carries water and nutrients that enter the plant in the root up through the stem and out to all parts of the leaf
• Phloem - Runs parallel to the xylem and carries sugar that is produced in the leaves, dissolved in fluid, to all parts of the plant
• Meristematic Tissue - A tissue in plant that divide continuously to bring plant growth (continuous cell division and growth)
• Primary growth – increases stem and root length
• Secondary growth – increases stem and root diameter
• Meristematic tissues have the ability to divide, hence they continuously produce new cells which keep differentiating to form specialized cells of plant.
• Apical Meristem – present at the growing tips of stems and roots. It is found at the apices of the stem and roots

  Main function – to increase the length of stems and roots
• Intercalary Meristem – present at the base of leaves or internodes. It is found at the base of the internodes leaves

  Main function – for the longitudinal growth of plants
• Lateral Meristem – present on the lateral sides of stem and roots. It occurs laterally in the axis, parallel to the sides of stems and roots

  Main function – to increase the thickness of stems and roots
• Permanent Tissue is a group of cells in which the growth has either stopped completely or for the time being. These cells may be dead or alive thin walled or thick walled
• Simple - Consist of only one type of cells
• Complex - Made up of more than one type of cells
• Plant tissue systems

  1. Ground tissue system
  2. Vascular tissue system
  3. Dermal tissue system
• Types of Permanent Tissues

  1. Simple Tissue
  2. Complex Tissue
  3. Special or Secretory Tissues
• Simple Permanent Tissue is a group of cells which are all alike in origin, form and function
• PARENCHYMA

  • Oval, spherical or polygonal in shape
• PARENCHYMA

  • They have thin cell wall
• PARENCHYMA - their cells walls are made up of cellulose
• PARENCHYMA - They may or may not be intercellular spaces between them
• PARENCHYMA - they are living cells and contain dense cytoplasm
• Function of Parenchyma

  • Storage of food material
  • Maintaining the turgidity of cells
  • They give mechanical strength to the stems of herbaceous plants
  • Allow transport of water and mineral salts in plants due to being thin walled
  • Photosynthesis
• COLLENCHYMA - Consist of elongated cells with corners which may be circular, oval, or polygonal in a cross section
• COLLENCHYMA - They have thin cell walls but are irregularly thickened at corners where number of cells join together
• COLLENCHYMA - The corners are thickened due to extra deposition of cellulose and pectin
• COLLENCHYMA - There is no intercellular space between the cells
• COLLENCHYMA - Living cells and have a distinct nucleus and dense cytoplasm
• COLLENCHYMA - They often contain chloroplasts
• Function of Collenchyma

  • Their primary function is to give mechanical support to herbaceous plants
  • They contain chloroplast which is used to manufacture sugar
• SCLERENCHYMA - When matured are dead without any protoplasm
• SCLERENCHYMA - They are long, narrow and thick-walled cells with tapered ends