Mr Exham youtube vids

• Plant transport system

  1. Network of veins or vascular bundles from roots to leaves

  2. Xylem vessels transport water and minerals ions

  3. Phloem vessels transport glucose and amino acids
• Vascular bundles in plant stem

  • Arranged around the outside of the stem
  • Phloem around the outer areas
  • Xylem within the phloem
• Xylem


  Transports water and dissolved minerals from roots to leaves in one direction
• Xylem


  • Made of dead cells with cytoplasm and cell walls removed
  • Strengthened by lignin
• Phloem


  Transports products of photosynthesis (sugars, amino acids) to all parts of the plant
• Translocation


  Movement of substances up and down the plant in the phloem to where they are needed
• Plant reproduction


  1. Gamete formation

  2. Pollen production

  3. Egg production

  4. Pollination

  5. Fertilization

  6. Seed and fruit production

  7. Seed dispersal

  8. Germination

  9. Offspring production
• Stamen


  The male parts of a flower, consisting of the anther and filament
• Anther


  The part of the stamen where pollen is produced
• Filament


  The part of the stamen that holds the anther in position
• Petals


  Attract insects to the flower for pollination
• Nectar


  A sugary liquid produced by flowers to attract insects
• Stigma


  The part of the female carpel that receives pollen during pollination
• Style


  The part of the female carpel that connects the stigma to the ovary
• Ovary


  The part of the female carpel that contains the ovules
• Ovule


  Contains the female gamete (egg)
• Carpel


  The collective name for the female parts of a flower (stigma, style, ovary)
• Pollination


  Pollen transfer from anther to stigma
• Cross-pollination


  • Pollen transferred from one flower to the stigma of another flower
• Self-pollination


  • Flower pollinates itself
• Characteristics of insect-pollinated flowers

  • Bright petals
  • Attractive Scent
  • Sticky stigma
  • Enclosed anthers
  • Nectar production
• Characteristics of wind-pollinated flowers


  • No bright petals
  • No scent
  • Feathery stigma
  • Many anthers
  • No nectar production
• Pollen grains in wind-pollinated flowers are small and inflated to be carried by the wind
• Key core practicals and experiments

  • Show that starch is produced in photosynthesis
  • Demonstrate how oxygen is given off by a water plant in photosynthesis
  • Show how light and chlorophyll are required for photosynthesis
  • Show how carbon dioxide is required for photosynthesis
• Test a leaf for starch

  1. Boil leaf in water to kill it

  2. Boil leaf in ethanol to remove chlorophyll

  3. Rinse leaf and spread on white tile

  4. Add iodine

  5. Observe colour change
• Leaf kept in dark


  Leaf de-starched
• Prove chlorophyll is required for photosynthesis


  1. Use variegated leaves

  2. Test areas with and without chlorophyll for starch
• Prove CO2 is required for photosynthesis


  1. Use soda lime in sealed jar with plant

  2. Absorbs CO2

  3. No starch produced
• Measure oxygen production by pond weed

  1. Count bubbles produced in 1 minute

  2. Repeat experiment

  3. Vary light intensity

  4. Vary CO2 levels
• Independent variable


  The variable you change in the experiment
• Dependent variable


  The variable you measure as the result
• Measuring volume of gas produced gives more accurate results than just counting bubbles
• Plant reproduction

  1. Gamete formation

  2. Pollen production

  3. Egg production

  4. Pollination

  5. Fertilization

  6. Seed and fruit production

  7. Seed dispersal

  8. Germination
• Fertilization


  1. Pollen lands on stigma

  2. Pollen tube grows down style

  3. Pollen nucleus enters ovule

  4. Pollen nucleus fuses with egg nucleus
• Zygote


  Fertilized egg cell
• Seed

  • Contains baby root (radicle)
  • Contains baby shoot (plumule)
  • Contains food store (cotyledon)
• Seed dispersal


  • Hooks to stick to animals
  • Eaten in fruits and dispersed in droppings
  • Explosive mechanisms
  • Parachute structures
  • Winged structures
• Plants want to disperse their seeds far from the parent plant to give them the best chance of survival
• Dormant state


  State of a seed that won't start growing further into a plant unless conditions are right
• Conditions for germination


  • Water
  • Temperature
  • Oxygen