Structures and Processes of Life: Plants

• The part of the plant that grows above the ground is the shoot
• The part of the plant that grows in the soil is the root
• Flowering plants have 4 organs: root, stem, leaf and flower
• The root anchor and supports the plant, absorbs water and minerals and sometimes can store food and water.
• The stem supports the bud, leaves and flowers, carries water and minerals, carries food and sometimes can store food and water
• The leaf photosynthesises, sometimes can store food, allows for exchange of gases and provides protection
• The role of the flower is to allow sexual reproduction take place
• Xylem tissue transports water and minerals
• Phloem tissue transports food
• the loss of water vapour from the surface of a plant is called transpiration
• stomata are small pores on the underside of leaves through which gases and water pass out of the plant
• the directional growth of a plant to a stimulus is called a tropism
• phototropism is the growth of a plant towards light
• geotropism is the growth of a plant in response to the force of gravity
• hydrotropism is the growth of a plant in response to moisture
• reproduction is the ability to produce new individuals of the same species
• There are two forms of reproduction: asexual and sexual.
• In asexual only one parent is involved, the new individuals are clones (genetically identical) to the parent, no gametes are produced and no fertilisation takes place
• a new stem called a runner is produced at the base of the parent plant and grows across the surface of the grund. a bud at its tip produces a new root and shoot system
• the new plant stays connected to the parent for a while to acces water, minerals and food before the runner stem dies away
• the artificial control of asexual reproduction is called vegetative propagation
• cuttings can be taken from the stem, root or leaf, grafting involves joining plants together and micropropagation involves taking a small sample of a plant and growing it in a lab
• sexual reproduction

  • male and female flower parts involved
  • each parent produces gametes
  • the gametes fuse during fertilisationto produce a zygote whivh develops to a seed
  • the offspring produced are genetically different to eachother and the parents
  • a fruit may form to help disperse the seed
• the male organs are the stamens
• the female organas are the carpels
• the anther prodices pollen and the filament positions the anther so the pollen can be blown away or picked up
• the stigma acts as a landing area for pollen, the style positions the stigma and the ovary develops the fruit and contains ovules which produce the eggs
• stages of sexual reproduction

  1. pollination
  2. fertilisation
  3. seed (and fruit) formation
  4. seed (and fruit) dispersal
  5. germination
• Pollination


  1. Pollen transfer from anther to stigma

  2. Carried out by wind, insects or other animals
• Pollination


  • Pollen caught by stigma
  • Pollen carried by insect
  • Pollen blown by wind
• Hay fever is caused by pollen in the air
• Insect pollination


  • Anther
  • Nectary
• Wind pollination


  • Anthers hang outside flower
• Fertilisation


  1. Pollen grain lands on stigma

  2. Pollen tube grows

  3. Sperm delivered to egg

  4. Sperm and egg fuse to form zygote
• Zygote


  Fertilised egg
• Seed and fruit formation

  1. Embryo becomes part of seed

  2. Seed made up of embryo, food store and seed coat

  3. Ovary may develop into fruit
• Seed


  • Embryo with plumule and radicle
• Seed and fruit dispersal

  1. Animal dispersal

  2. Wind dispersal

  3. Water dispersal

  4. Self-dispersal
• Animal dispersal


  • Animals eat fleshy fruits and pass seeds in faeces
  • Seeds/fruits stick to animal fur
• Wind dispersal


  • Small, light seeds
  • Parachute-type fruit
  • Winged-type fruit