Fruit

3.4 - Plant Fertilisation

- Pollen grains on stigma - germinate and tube begins to grow downwards
- One tube goes down to ovule - nucleus travels down this tube - into ovule 
4 things will happen 
- 1. Pollen nucleus will fertilise the ovule --> formation of zygote --> grown in to embryonic plant 
- 2. outside of ovule forms seed coat (TESTA) 
- 3. Inside formation of seed (cotyledons) - food stores for the seedling -- supports plant until it develops first sets of leaves 
- 4. Thickening of the walls of the ovary/carpel - plant will put energy (sugars, proteins) - will form the fruit - developed from the wall. 

Flower Development Map

Diagram and Photo of a Lily

3.3 b - Wind Pollination

- Transfer of pollen grains from anther ---air (carried by wind)--- Stigma
- Adaptation - Light weight pollen grains with some sort of wing feature (move through air more effectively) 
                      - Anthers hang well clear of any basic flower structure, so exposed to the wind
                      - Stigma, really large surface area, feather like structure to catch pollen grains when       passing through air) 
- Grass - No colour in the petals and no scent to attract insects - No nectaries - no point to produce these, waste of energy when it is a wind pollinated plant 

3.3 a - Insect Pollination

- Pollinating flower - transfer of pollen grain from the anther of one plant to the stigma of another 
- Pollen - small structure contains male nuclei 
- Insects transfer 
- First flower needs to attract insect and have reason to go the the second 
- Cross pollination - when pollen goes from one plant to the other 
- Attraction Adaptation - Insect
   - Signals - Colour petals
                    - Scents 
   - Value - Food - Nectaries produces fructose 
                 - Pollen - Source of protein 


Structure - Petals
                 - Stamen (male part of the plant) - Anther (pollen grains), Filament 
                 - Carpel (female Part of the plant) - Stigma, Style and Ovary (ovules)