Adaptations for Pollination (Edexcel IGCSE Biology)

Insect-Pollinated Flowers

• Flowers are the reproductive organs of plants

• The role of flowers is to enable plant gametes to come together in fertilisation

  • The male gametes of plants are found in pollen grains

  • The female gametes of plants are in ovules

• The process by which pollen is transferred from the male part of a flower to the female part of a flower is known as pollination; this can be carried out in various ways, e.g. by insects or by wind

Insect-pollinated flower structure

Insect pollinated flowers are adapted to attract insects and aid insect pollination

Structural adaptations of insect-pollinated flowers

• Insect pollinated flowers are adapted to allow insects to collect pollen from one flower and easily transfer it to another flower

  • When an insect enters a flower in search of nectar it brushes against the anthers, which deposit sticky pollen onto the insect's body

  • When the insect visits another flower it brushes against the stigma and deposits some of the pollen from the first flower; this is pollination

Wind-Pollinated Flowers

Wind pollinated flower structure

• Wind-pollinated flowers do not need to attract insects, so their structure differs from that of insect-pollinated flowers

Wind pollinated flowers have anthers that hang outside the flower on long filaments, and feathery stigmas that can catch pollen easily

Structural adaptations of wind-pollinated flowers

• Wind pollinated flowers are adapted so that wind can easily catch pollen grains and carry them to the stigmas of other flowers

• The anthers and stigmas of wind pollinated flowers hang outside the flower so that:

  • pollen can easily be blown away by the wind

  • pollen can easily be caught by the stigmas of other flowers