Plants

• Insect pollinated flowers

  • have brightly coloured petals
  • produce sweet nectar
  • sticky pollen in small quantities
  • anthers are enclosed in the flower
  • stigma is enclosed
• Wind pollinated flowers

  • small or no petals
  • dont have nectaries
  • light, smooth pollen grains in large amounts
  • Anthers and stigmas hang outside the flower
• The growth of the pollen tube from a pollen grain leads to fertilisation and seed and fruit formation
• Germination


  1. Seed coat splits

  2. Roots and shoots emerge

  3. Growing into a seedling
• Seed germination process


  1. Seed absorbs water through micropyle

  2. Activates enzymes to start breaking down food store

  3. Embryo gets energy to start growing roots and shoots

  4. Seed swells and surface breaks open
• Seedling growth


  Young seedling's leaves become large enough to begin photosynthesising and make its own food
• Environmental conditions needed for germination

  • Warmth
  • Water
  • Oxygen
• Natural Asexual Reproduction

  Reproduction in Plants
• Runner


  • Horizontal stems which grow across the surface of the ground
• Runners


  • Tubers (e.g. potatoes)
• Root tubers


  1. Produce new shoots

  2. Shoots grow

  3. Stored reserves of the root-tuber are consumed

  4. Producing new roots, stems and reproductive organs
• Bulbs


  • At the base of the plant is a bulb
  • The bulb splits, forming little bulbs which then develop into a new plant
• Bulbs


  • e.g. daffodils
• • During Germination, the absorption of Water triggers the production of plant hormones, thus stimulating the synthesis of Amylase
  • Amylase breaks down food reserves of Starch found in Cotyledon into Glucose to be used as an energy source for growth via aerobic respiration
  • This continues until Seedling can carry out Photosynthesis as a source of glucose for energy
• • In Runners, cells split off from parent plant to grow side branches that forms Plantlets, specialising into root hair cells
  • As a result, Plantlets will grow roots and plant will evolve, forming plant that is genetically identical to parent plant via asexual reproduction (clone)
• • In Cuttings, specific plant tissue (typically undifferentiated shoot) is selected from stock plant and sterilised
  • Tissue sample is then explanted and grown in petri dish containing sterile nutrient agar gel
  • Explant is treated with growth hormones (auxins) to stimulate Shoot and Root development
  • As a result, growing Shoot can be continuously divided and separated to form new samples
  • Once Root and Shoot are developed, the cloned plant is then transferred to Soil