Flowers and pollination

Identify the main male and female parts of a flower (stamen, carpel) and their components (anther, filament, stigma, style, ovary), and state their basic functions in reproduction.
Define pollination, and differentiate between self-pollination and cross-pollination.
Describe the key adaptations of insect-pollinated and wind-pollinated flowers.

Just like animals, plants need male and female parts to come together to reproduce.
For a seed to develop, pollen (male) needs to reach an ovule (female) inside the ovary.
This transfer of pollen from the anther to the stigma is called pollination.
Pollination can happen in two main ways:
- Self-pollination: Pollen moves from the anther to the stigma on the same plant.
- Cross-pollination: Pollen travels from the anther of one plant to the stigma of a different plant (of the same species).
Pollen needs help to travel. The two main ways pollen gets transferred are by wind and by insects.

Insect-Pollinated Flowers
Many flowers rely on insects like bees to move their pollen. These flowers are adapted to attract them:
- Brightly coloured petals: To catch the insect's eye.
- Sweet scents: To attract insects from a distance.
- Nectar: A sugary liquid deep inside the flower that insects feed on. As the insect collects nectar, it brushes against the anthers and gets covered in pollen.
- Sticky or spiky pollen: Helps it stick to the insect's body.
- Stigma is often sticky: Helps to grab the pollen when the insect visits another flower.
When the insect visits another flower for more nectar, some of the pollen rubs off onto the new flower's stigma. Pollination has happened.
Many foods we eat, like apples, strawberries, and nuts, come from plants pollinated by insects.

Some plants, especially grasses and many trees, use the wind for pollination. Their flowers are adapted differently:
- Small petals: Often dull green or brown, as they don't need to attract insects.
- No nectar or strong scent.
- Lots and lots of pollen: They produce huge amounts because wind pollination is random – much of the pollen gets lost.
- Lightweight and smooth pollen: Easily carried by the wind.
- Long filaments: Hang the anthers outside the flower so the wind can catch the pollen.
- Large, feathery stigmas: Provide a big surface area to trap pollen blowing in the wind.
If you suffer from hay fever, you are likely allergic to the lightweight pollen from wind-pollinated plants.

Flower: The reproductive structure of a plant.
Stamen: The male part of a flower, consisting of the anther and filament.
Anther: The part of the stamen that produces pollen.
Pollen: The male gamete (sex cell) of a plant.
Carpel: The female part of a flower (sometimes called the pistil), consisting of the stigma, style, and ovary.
Stigma: The sticky top part of the carpel that receives pollen.
Ovary: The base of the carpel containing the ovules, where seeds develop after fertilisation.
Ovules: The female gametes (sex cells) of a plant, found inside the ovary.
Pollination: The transfer of pollen from the anther to the stigma.
Adaptations: Features that help an organism (or a part of an organism like a flower) survive or function effectively in its environment.

Research the ecological and economic importance of insect pollinators (like bees) for both wild ecosystems and human food production, and investigate current threats to pollinator populations.
Compare the structures of real or detailed illustrated examples of wind-pollinated flowers (e.g., grass flowers, oak catkins) and insect-pollinated flowers (e.g., roses, lilies), specifically pointing out how their features are adapted for their different pollination methods.