BIOLOGY

• Simplue Tissues


  • Parenchyma
  • Sclerenchym
  • collenchyma
• Complex Tissues

  • Epidermis
  • Peridermis
  • Xylem
  • Phloem
• Plant organs


  • Roots
• Roots develop from a part of a root called "hypocotil"
• Types of roots


  • Taproot
  • Fibrous
• Taproot


  • Has primary & lateral roots
  • Found in dicots
• Fibrous root


  • No primary root, only lateral roots
  • Found in monocots
• Root regions


  • Root cap
  • Meristema to Region
  • Elongation Region
  • Maturation Region
• Root cap


  Thimble shaped, protects the root tip
• Mucige


  Slimy substance that protects the root tip from being wounded
• Meristema to Region


  Domed shaped, actively dividing cells (mitosis)
• Elongation Region


  Cells undergo enlargment
• Maturation Region


  Cells differentiated to form permanent tissues
• Epidermis


  Outer section of the root
• Epidermis


  • Consists of cuticle
  • Lacks stomata, no gas exchange
  • For protection, absorbs minerals, dissolves nutrients
• Simple Tissues


  • Parenchyma
  • Sclerenchym
  • Collenchyma
• Complex Tissues

  • Epidermis
  • Peridermis
  • Xylem
  • Phloem
• Plant Organs

  • Roots
  • Stems
  • Leaves
  • Flowers
  • Fruits
  • Seeds
• Taproot

  Has primary & lateral roots, found in dicots
• Fibrous root


  Has no primary root, only lateral roots, found in monocots
• Root Regions

  1. Root cap

  2. Meristematic Region

  3. Elongation Region

  4. Maturation Region
• Root cap

  • Thimble shaped, protects the root tip, secretes a slimy substance called "mucige"
• Meristematic Region


  • Domed shaped, actively dividing cells (mitosis)
• Epidermis


  • Outer section of root, consists of cuticle, lacks stomata, absorbs minerals, dissolves nutrients
• Cortex


  • Has parenchyma cells for storage, consists of 3 layers: hypodermis, middle layer, endodermis
• Stele


  • The central cylinder of the root, contains pericycle, vascular tissues, pith
• Monocot


  1 cotyledon, flower parts in multiples of 3, leaves are parallel and long/slender, vascular bundles are scattered
• Dicot


  2 cotyledons, flower parts in multiples of 4-5, leaves are branched and broad, vascular bundles are arranged in a ring
• Stem


  • Originates from the epicotyl, functions: support, storage, transportation
• Types of Stems

  • Herbaceous
  • Woody
• Herbaceous Stem


  • Soft & green, covered with epidermis, small in diameter
• Woody Stem


  • Tough & not green, undergoes secondary growth, considerably grows in length & diameter, covered with cork cells
• Stem Structures

  • Nodes
  • Internodes
  • Lenticels
  • Leaf scars
  • Buds
  • Bud scales
  • Bud scar
• Classification of Buds

  • Terminal
  • Lateral
  • Flower
  • Leaf
  • Naked
  • Covered
  • Active
  • Dormant
• Woody Stem Internal Structure

  • Bark (cork cambium, cortex, phloem)
  • Wood (xylem, annual rings)
• Herbaceous Stem Internal Structure

  • Epidermis
  • Cortex (chlorenchyma cells)
• Leaf Classification

  • Phyllotaxy (alternate, opposite, whorled)
  • Number of leaf blades (simple, compound)
  • Venation (parallel, netted)
  • Margin (entire, serrate, lobed)
• Flower


  • Located at the apex, meristematic tissue, absence of continuous growth
• Essential Flower Parts

  • Pistil (stigma, style, ovary)
  • Stamen (anther, filament)
• Accessory Flower Parts

  • Sepal
  • Petal
  • Receptacle
  • Peduncle