By the end of this lesson
- Identify reproductive structures in a flower.
- Compare insect- and wind-pollinated flowers.
- Explain adaptations in terms of pollen transfer.
BIG QUESTION
How can flower anatomy reveal the way pollen is transported?
Petal, pollen, anther and stigma features match the pollinating agent.
Flowers contain male and female organs
The antherThe part of the stamen that makes and releases pollen grains. produces pollen and is held on a filament; together they form a stamen. The stigmaThe sticky tip of the carpel in a flower that receives pollen., style and ovary form the carpel.
Ovules develop inside the ovary. Sepals protect the flower bud, while petals may attract animal pollinators.
Insect-pollinated flowers advertise and attach
Large coloured petals, scent and nectar attract insects. Anthers and sticky stigmas are usually held inside so visiting insects brush against them.
Pollen grains are relatively large, sticky or spiky, helping them attach to bodies.
Wind-pollinated flowers expose and intercept
Small dull petals and no nectar avoid unnecessary investment. Exposed dangling anthers release large quantities of small, light, smooth pollen.
Large feathery stigmas project outside and provide a broad surface for intercepting airborne pollen.
Pollination syndromes
Each feature should be linked to pollen transport.
| Feature | Insect pollination | Wind pollination |
|---|---|---|
| Petals/scent/nectar | Prominent attractants. | Reduced or absent. |
| Anthers | Firm and inside flower. | Exposed and dangling. |
| Stigma | Sticky and inside. | Large, feathery and exposed. |
| Pollen | Fewer, larger, sticky/spiky grains. | Many small, light, smooth grains. |
| Function | Adheres to visiting animal. | Released and intercepted from air. |
Language that earns precision
- pollination
- Transfer of pollen from anther to stigma of a flower of the same species.
- anther
- Part of a stamen that produces pollen.
- stigma
- Surface that receives compatible pollen.
- ovule
- Structure in the ovary containing the female gamete nucleus.
Common misconceptions
Claim: Pollination is fertilisation.
Correction: Pollination transfers pollen; fertilisation later fuses gamete nuclei.
Claim: Wind-pollinated flowers have no adaptations.
Correction: They have specialised exposed anthers, feathery stigmas and light pollen.
Claim: All brightly coloured flowers are insect-pollinated.
Correction: Features provide evidence but pollination biology can be more varied.
Match the answer to the command word
Give paired structural differences.
State feature, then how it improves pollen transfer.
Recall, apply, then justify
Explain three adaptations of a wind-pollinated flower.
Hint
Choose exposed anthers, light pollen or feathery stigma.
Suggested marking points
- Exposed dangling anthers release pollen easily into air.
- Many small light pollen grains are readily carried by wind.
- A large feathery exposed stigma intercepts airborne pollen.
Compare pollen from insect- and wind-pollinated flowers.
Hint
Number and surface/size.
Suggested marking points
- Insect-pollinated flowers make fewer, larger, sticky or spiky grains.
- Wind-pollinated flowers make many small, light and smooth grains.
A flower has tiny petals, exposed anthers and a compact sticky stigma. Evaluate the evidence for wind pollination.
Planning hint
Use supporting, conflicting and missing evidence.
What a strong design includes
- Tiny petals support wind pollination because animal attraction is reduced.
- Exposed anthers support easy release into moving air.
- A compact sticky stigma is less typical of wind pollination.
- A feathery exposed stigma would intercept airborne pollen more effectively.
- Pollen size, abundance and surface would provide further evidence.
- The flower may use another pollinator or show a mixed pollination strategy.