Flowers and pollination
Inside a flower
- A flower is a plant's organ for sexual reproduction.
- It has male and female parts.
| Part | Function |
|---|---|
| sepals | protect the bud before it opens |
| petals | large and colourful, attract insects |
| stamens (male) | a filament holding an anther that makes pollen |
| carpel (female) | a stigma, a style and an ovary holding ovules |
Practice
The male part of a flower that makes pollen is the:
The stamen is male: its anther makes pollen. The carpel (stigma, style, ovary) is female.
Pollination
- Pollination is the transfer of pollen from an anther to a stigma.
- Insect-pollinated: bright petals, scent, nectar; sticky/spiky pollen.
- Wind-pollinated: small dull petals; anthers and stigmas hang outside; light, smooth pollen.
Practice
Pollination is the transfer of pollen from:
Pollination moves pollen grains from an anther (male) to a stigma (female).
Practice
A wind-pollinated flower usually has:
Wind flowers are dull with anthers/stigmas hanging out and light smooth pollen; insect flowers are showy with sticky pollen.
Self vs cross (Supplement)
- Self-pollination: pollen lands on the stigma of the same plant.
- Cross-pollination: pollen carried to a different plant of the same species.
- Cross-pollination gives more variation but relies on pollinators or wind; self-pollination is more reliable but gives less variation.
Practice
Cross-pollination gives more variation than self-pollination.
Cross-pollination mixes genes from different plants, giving more variation (but it depends on pollinators or wind).
You've got it
Key idea
- male = stamen (anther makes pollen); female = carpel (stigma, style, ovary with ovules)
- pollination = anther → stigma; insect flowers are showy, wind flowers small with parts hanging out
- (Supplement) cross-pollination → more variation; self-pollination → more reliable