Insect-pollinated flowers attract animals that carry pollen, and wind-pollinated flowers release light pollen into the air. Each feature fits one of these two methods.
This lesson follows flower structures. The next is double fertilisation.
How do the two flower types differ?
| Feature | Insect-pollinated | Wind-pollinated | Reason |
|---|---|---|---|
| Petals | Large, colourful | Small and dull, or absent | Insects are attracted by colour, wind is not |
| Scent and nectar | Present | Absent | Insects visit for food |
| Pollen | Sticky or spiky, smaller amount | Light and smooth, large amount | Sticky grains cling to insects, and light grains travel in air |
| Stigma | Small, inside the flower | Large and feathery, outside | A large stigma catches pollen in the air |
| Anthers | Inside the flower | Hanging outside | Wind can blow the pollen away |
Worked example: building a comparison
An original question: “Compare the pollen of a hibiscus flower, which is pollinated by insects, and of a grass, which is wind-pollinated.”
The answer, in linked sentences:
“The hibiscus produces sticky pollen in smaller amounts, whereas the grass produces large amounts of light, smooth pollen. This is because insects carry hibiscus pollen directly to the next flower, but the wind scatters grass pollen at random, so most grains are lost. Both flowers produce pollen in their anthers.”
The answer has a difference, a reason and a similarity. That is what a comparison needs.
The mistake that costs marks
The common error is to list features without a reason, or to place a feature in the wrong column, for example giving wind flowers bright petals.
| Version | Judgement |
|---|---|
| “Insect flowers have big petals. Wind flowers have feathery stigmas.” | A list, with no comparison |
| “Insect flowers have big petals to attract insects, whereas wind flowers have small petals because they do not need to.” | A linked comparison with a reason |
How do you check your answer?
For each feature, ask “why does this help?”. If you cannot give the reason in one short phrase, revise that feature.
Also check that every sentence names both flower types, or clearly signals a contrast with “whereas” or “however”.
Check yourself
Explain why a wind-pollinated flower has its anthers hanging outside the flower.
Answer
Anthers hanging outside are exposed to moving air, so the wind can easily blow the pollen grains away to other flowers. If the anthers were enclosed inside the petals, the wind could not carry the pollen out.
The link is: exposure leads to easy release, which leads to pollination by wind.
What to study next
Go on to explaining double fertilisation. The biological data interpretation trainer gives more comparison practice, and the mistake log is a place to note missing reasons.
If you want a teacher to keep asking “why” until your comparison is complete, see online one-to-one Biology tuition.