module 5

• Types of plant reproduction

  • Sexual
  • Asexual
• Sexual reproduction


  Involves male and female parts (gametes: egg cell + sperm cells)
• Asexual reproduction


  Only one parent is involved (no gametes)
• Characteristics of sexual reproduction


  • Involves the flowers
  • Involves formation of flowers, fruits & seeds
  • Pollination or fertilization
  • Produces genetically different offspring
  • Can spread more quickly over a large area
  • Always result in production of seeds
  • Plants are more likely to survive new threats
• Characteristics of asexual reproduction

  • Does not involve the flowering part of the plant
  • Does not involve formation of flowers, fruits & seeds
  • Fragmentation
  • Produces genetically identical offspring
  • Can only grow close to the parent plant
  • Can produce bulbs, runners & tubers
  • Plants are more vulnerable to new threats

  
• Pedicel (Peduncle)


  Flower stalk
• Receptacle (Torus)


  Holds the flower parts
• Flower appendages


  • Perianths (sepals + petals)
  • Stamens (male part)
  • Carpels (female part)

  
• Sepals


  Protects the flowers when in bud
• Petals


  Attracts pollinating insects
• Anther


  Lobes containing pollen sacs
• Filament


  Stalk that hold the anther
• Stigma


  Receives the pollen
• Style


  Supports the stigma
• Ovary


  Contains ovules that tore the female gametes
• Flower classification


  • Complete (possess all 3 appendages)
  • Incomplete (lacks one or more appendages)
  • Perfect (possess both stamen and carpel)
  • Imperfect (possess either a stamen or a carpel but not both)

  
• All complete flowers are perfect
• Not all perfect flowers are complete
• All imperfect flowers are incomplete
• Not all incomplete flowers are imperfect
• Ovary position


  • Hypogenous (superior ovary)
  • Perigenous (hypanthium surrounds the ovary)
  • Epigenous (inferior ovary)

  
• Funiculus


  Attaches the ovary to the ovule
• Structures of the ovule

  • Integuments (protective layer)
  • Nucellus (inner structure that develops into endosperm)
  • Embryo Sac (produces egg cells for fertilization)
  • Micropylar End (opening for pollen entry)
  • Chalazal End (where nucleus is joined by integuments)
  • Synergids (produce signals that guide the pollen)
  • Antipodals (cells with no established function)
  • Polar Nuclei (responsible for double fertilization)

  
• Pollination


  Transfer of pollen from anther to stigma
• Types of pollination


  • Self-pollination (same flower or another flower of the same plant)
  • Cross-pollination (flowers from different plants)
  • Wind pollination
  • Animal pollination
• Pollen grains


  Contains Microgametophytes (produce male gametes) of seed plants, have hard coat to protect sperm during movement, and germinate to produce pollen tubes
• Fertilization (Zyngamy)


  Fusion of gametes
• Inflorescence


  Groups of several flowers that may all open at the same time or follow an orderly progression to maturation
• Pedicels


  Little stalks attached to each peduncle of an inflorescence
• Types of inflorescence


  • Spike
  • Spadix
  • Panicle
  • Cyme
  • Corymb
  • Umbel
  • Capitulum/Head
  • Cyanthium
  • Verticillaster
  • Hypanthodium

  
• Spike


  Elongated axis with flowers that are sessile or without a stalk
• Spike


  • Pansit-pansitan (Peperomia pellucida)
• Spadix


  Spike with fleshy axis, enclosed by large, often brightly colored bract called SPATHE
• Spadix


  • Calla lily (Zantedeschia aethiopica), Anthurium (Anthurium andraeanum)
• Panicle


  Main axis of the flower is branched and the lateral branches bear the stalked flowers
• Panicle


  • Rice (Oryza sativa), Malunggay (Moringa oleifera)
• Cyme


  Main axis ends in a flower that opens before the flowers below or on its side open. Further growth takes place with the growth of one or more laterals. The flowers may be with or without stalks.
• Cyme


  • Baby's breath
• Corymb


  The main axis is comparatively short. The lower flowers have longer stalks than the upper ones so that all the flowers are brought more or less at the same level.
• Corymb


  • Caballero (Caesalpinia pulcherrima)