In this module, you will learn:
- The definition of pollination
- The agents of pollination
- The differences between insect and wind pollinated flowers
Resources to help you:
- Textbook: page 132, 133, 134 and 135
- Notebook: page 34
Watch the video
Learn about pollination and a recap of the parts of flowers.
Source: https://www.youtube.com/watch?v=W-daJxfe4As
You can change the speed to 0.75x to make it easier to listen.
European honey bee extracts nectar
Credit: John Severns (Severnjc), Public domain, via Wikimedia Commons
What is pollination?
Pollination is the transfer of pollen grains from an anther to a stigma of a flower. It can be a transfer within the same flower or flowers of same plant, i.e. self-pollination, or within different flowers of different plants, i.e. cross-pollination.
What are pollen grains?
Pollen grains contain the male gametes or male sex cells of the plant. They are produced at the anthers of the flower.
Agents of Pollination
An agent of pollination helps transfer pollen grains from the anther to the stigma.
The two main agents of pollination are:
- insects such as bees and butterflies
- wind
When a butterfly visits a flower for nectar, pollen grains are stuck to its body to help in pollination.
Credit: @phbcz via YayImages
A strong gust of wind can carry the pollen grains.
Credit: @damiangretka via DepositPhotos
Source: https://www.youtube.com/watch?v=MQiszdkOwuU
Insect Pollination
The process of insect pollination involves:
- The insect is attracted to the brightly coloured petals of the flower in search of nectar.
- As the insect feed on the nectar (which is usually inside the flower), the insect has to get its body close to the anther of the flowers.
- The pollen grains from the anther gets stuck to the insect.
- The insect leaves the flower to find others.
- When the insect gets more nectar from the second flower, the pollen grains which was stuck on the body gets transferred to the stigma of the newly visited flower.
- Pollination is completed.
Characteristics of insect-pollinated flower
The characteristics of insect-pollinated flowers are as follows:
- large and brightly-coloured petals
- scented (have smell)
- produce nectar
- stamen and stigma are found inside the flower
- pollen grains are spiky and sticky
Insect pollinated flower have brightly coloured petals to attract insect.
Credit: @kaylee229 via Twenty20
An animation of how wind pollination occurs
Source: https://www.youtube.com/watch?v=Z_nFfmDLDwA
Wind Pollination
In wind pollination, plants rely on the wind to blow over the flower and the pollen grains gets carried by the wind to the stigma of another flower.
Characteristics of wind-pollinated flowers
The characteristics of wind-pollinated flowers are as follows:
- dull-coloured flowers (no need to attract insect)
- small petals or no petals at all (no need to attract insect)
- not scented (no smell)
- do not produce nectar (no need to attract insect)
- stigma is feathery (larger surface area to receive pollen)
- pollen grains are very light (easily carried by the wind)
The anthers (reddish colour) of the maize plant hangs outside to allow wind to pick up the pollen grains.
Credit: @ChWeiss via DepositPhotos
Ready for the next module?
In the next module, we will look at the fertlisation in plants and the formation of fruits and seeds.