Photosynthesis Bio

• Sequence of biological organisation

  1. Cells

  2. Tissues

  3. Organs

  4. Whole organisms
• Plant systems

  • Root system below the soil
  • Shoot system above the soil
• Photosynthesis


  The process by which plants make their own food
• Leaves have large surface area to catch light, are packed with chlorophyll to trap sunlight, have tiny holes to allow gases in and out, and are thin so materials can easily move.
• Photosynthesis requires light energy, carbon dioxide, and water.
• The products of photosynthesis are glucose and oxygen.
• Uses of glucose produced by photosynthesis

  • To release energy for cells
  • To make new cells in leaves
  • Stored as starch
  • Transported to parts of plant that cannot photosynthesise
• Roots and flowers cannot photosynthesise because they are underground/do not contain chlorophyll.
• Leaves store the food (glucose) produced by photosynthesis as starch.
• The leaf starch test uses iodine to show the presence of starch in leaves.
• Factors affecting photosynthesis


  • Light
  • Carbon dioxide
  • Water
  • Temperature
• Limiting factors are the environmental conditions that can restrict the rate of photosynthesis.
• Genetic engineering is the process of modifying the genes of an organism.
• Minerals needed for healthy plant growth

  • Magnesium
  • Nitrogen (nitrates)
  • Calcium
• Types of fertilizer


  • Artificial (man-made chemicals)
  • Natural (manure/slurry)
• Artificial vs natural fertilizers

  • Artificial are high cost, quickly absorbed
  • Natural are low cost, slowly released
• What is calcium used for?

  strengthen cell walls
• what is magnesium for?

  makes chlorophyll
• what is nitrogen for?

  makes protein
• what is the the flower?

  male ans female parts to make new leaves
• Root


  • Part of the plant that grows underground
  • Absorbs water and nutrients from the soil
  • Anchors the plant in the ground
• Flower


  • Contains the male and female parts of the plant
  • Produces seeds for reproduction
• Leaf


  • Produces food for the plant through photosynthesis
  • Large surface area to trap sunlight
  • Contains chlorophyll
  • Has pores to allow gases in and out
• Bud


  • Develops into new flowers and leaves
• Stem


  • Supports the plant and holds it upright
  • Transports water and nutrients from the roots to the leaves
• Parts of a plant

  • Root
  • Flower
  • Leaf
  • Bud
  • Stem
• The root, flower, leaf, bud, and stem are the 2 main systems of a plant
• The male and female parts of the plant work together to produce new seeds
• The plant uses photosynthesis to make food for itself
• Petiole


  • Attaches the leaf to the stem
• Midrib


  • Supports the leaf and helps move food and water
• Lateral veins


  • Branch off from the midrib
• Leaves have a large surface area to trap sunlight for photosynthesis
• Leaves are thin so materials don't need to move far for light
• Leaves contain chlorophyll
• Leaves have pores to allow gases in and out