Plant Reproduction

• asexual reproduction


  process of reproduction involving a single parent that results in offspring that are genetically identical to the parent (mitosis)
• sexual reproduction


  A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents (meiosis)
• Fertilisation


  the fusion of a male and female gamete to produce a zygote that undergoes cell division and develops into an embryo
• Stamen


  The male reproductive part of a flower
• Style


  The stalk of a flower's carpel, with the ovary at the base and the stigma at the top.
• stigma


  end bit that pollen grains attach to
• Anther


  produces pollen
• filament


  Supports the anther
• carpel


  The female reproductive organ of a flower, consisting of the stigma, style, and ovary.
• Ovary


  In flowers, the portion of a carpel in which the egg-containing ovules develop.
• Pollination


  transfer of pollen from anther to stigma
• self-pollination


  the transfer of pollen grains from an anther to the stigma of the same flower or to the stigma of another flower on the same plant
• cross-pollination


  a reproductive process in which pollen from one plant is transferred to the stigma of another plant
• Characteristics of a insect pollinated flower

  Position of stamens : inside flower

  Position of stigma : inside the flower

  Size of petals : large

  Colour of petals : brightly coloured

  Nectaries : present and sweet

  Pollen grains : large and heavy, small numbers
• Characteristics of wind pollinated flower

  Position of stamens : outside flower, exposed to wind

  position of stigma: outside, feathery to catch pollen

  size of petals : small

  colour of petals: green

  Nectaries : absent

  Pollen Grains : small + light, large numbers
• Double fertilisation in plants

  • after pollen lands on stigma -> pollen tube grows down the style to ovary
  • Sperm nucleus travels down pollen tube -> ovule
  • Sperm nucleus fuses with nucleus of egg cell = zygote
• Seed and fruit formation

  • after fertilisation the ovule develops into a seed
  • Ovary becomes fruit which covers the seed
• RP: conditions for germination

  Test tube A: dry cotton wool

  Test tube B: moisten cotton wool with water

  Test tube C: cover seeds and cotton wool with water and add a layer of oil on top

  test tube D: moisten cotton wool and place tube in fridge
• Germination

  • embryo grows into a seedling
  • Water absorption splits the testa allowing the plumule and radicle to emerge
  • Water activates enzymes through micropyle
  • cotyledons -> amylase converts starch into glucose
  • Seed needs oxygen for aerobic respiration to release energy for growth
• How can plants reproduce asexually?

  Runners: horizontal stems that grow sideways out of the parent plant

  Grow roots when they touch soil and become independent from parent plant

  micropropagation
• How can you tell if a seed has germinated?

  Radicle will have grown, producing a shoot