Flower Structure & Pollination IGCSE Biology

Flower Structure and Pollination: Wind vs Insect

Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.

Key concept

Flowers contain male parts (stamens with anthers producing pollen) and female parts (carpels with stigma, style and ovary). Pollination is the transfer of pollen from anther to stigma, either by wind or by insects.

Flower structure diagrams appear frequently in Paper 2 and Paper 4. Students must be able to label all parts, state the function of each, and compare the adaptations of wind-pollinated and insect-pollinated flowers.

Parts of a flower and their functions

Part	Function
Sepal	Protects the flower bud before it opens
Petal	Attracts insects with colour and scent (in insect-pollinated flowers)
Anther	Produces pollen grains containing the male gamete
Filament	Supports the anther; together with anther forms the stamen
Stigma	Receives pollen grains; often sticky or feathery
Style	Connects the stigma to the ovary; pollen tube grows through it
Ovary	Contains ovules, each with a female gamete (egg cell)
Ovule	Develops into a seed after fertilisation

Pollination defined

Pollination is the transfer of pollen grains from the anther to the stigma of a flower. Self-pollination is transfer within the same flower or between flowers on the same plant. Cross-pollination is transfer between flowers on different plants of the same species.

Cross-pollination increases genetic variation because it combines alleles from two different parent plants. Self-pollination reduces variation but is more reliable when pollinators or other plants are scarce.

Insect-pollinated vs wind-pollinated flowers

Feature	Insect-pollinated	Wind-pollinated
Petals	Large, brightly coloured, scented	Small, dull, often absent
Nectar	Present to attract insects	Absent
Pollen	Sticky, spiky, larger grains	Smooth, light, small, produced in large quantities
Anthers	Inside flower, positioned to brush against insect	Exposed, hanging outside flower to release pollen into wind
Stigma	Sticky, inside flower	Large, feathery, hanging outside to catch airborne pollen

Each structural difference is an adaptation to the method of pollen transfer. Exam answers should link each feature to its function rather than just listing differences.

From pollination to fertilisation

After a pollen grain lands on the stigma, it germinates and grows a pollen tube down through the style to the ovary. The male gamete nucleus travels down the pollen tube and fuses with the female gamete (egg cell) in the ovule. This fusion is fertilisation.

After fertilisation, the ovule develops into a seed, and the ovary develops into a fruit. The fruit protects the seeds and aids in their dispersal.

Try a focused question (4 marks)

Describe two differences between the flowers of a wind-pollinated plant and an insect-pollinated plant.

Show the answer and marking guidance

Wind-pollinated flowers have small or absent petals, while insect-pollinated flowers have large, colourful petals to attract insects.
Wind-pollinated flowers produce large quantities of small, smooth, light pollen, while insect-pollinated flowers produce smaller quantities of sticky or spiky pollen that attaches to insect bodies.

Original Cambridge-style practice written for this site. It is not an official Cambridge past-paper question.

Common mix-ups to avoid

Check these points against your own answer before moving on.

Confusing pollination with fertilisation (pollination is pollen transfer; fertilisation is gamete fusion).
Saying wind-pollinated flowers have no pollen (they produce much more, but it is lightweight).
Describing petal colour without linking it to attracting insects.
Forgetting that the stigma of wind-pollinated flowers is feathery to catch airborne pollen.