3.3a,b - Pollination

A plant consists of:
female part (carpel) which consists of the stigma, style, and the ovary
Male part (staman) which consists of the filaments and the anther


Insect pollination
-There has to be a transfer of pollen from the anther of a plant to the stigma of another plant (cross-pollination
(The pollen contains the 'male' nuclei)
-This takes place because of insects

-For this to happen the insects have to be attracted to the flower.
                                                         To attract an insect, the plant uses:
                                        -Signals --- Coloured petals
                                                     --- Scents (smell)
                                        -Value   --- food (in nectaries) - Fructose
                                                     --- Some insects eat pollen as a source of protein

Wind pollination:
                                    air
                   Anther ----------> stigma
                                  wind

The pollen has to be:
-Light weight
-Has some 'wing' feature which moves the pollen more efficiently

-The anther sticks out from the main parts of the flower so that it is exposed to the wind
-The stigma has a large surface area (featherlike structure) to catch the pollen grains as they move through the air.
- The plant has nothing to attract insects because it is a waste of energy