Question 1
Paper 4 short-answer style1 markDefine pollination. (1 mark)
Model answer
Pollination is the transfer of pollen grains from the anther to the stigma.
Why this scores
One mark for 'transfer of pollen from anther to stigma'.
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Detailed notes on Reproduction for Cambridge IGCSE Biology, covering key concepts, explanations, examples, and exam-focused revision points.
Flowers as reproductive organs. Pollination, fertilisation, seed formation. Insect-pollinated vs wind-pollinated have very different flowers.
Mapped to the Cambridge IGCSE 0610 syllabus (2026-2028).
Sepals + petals + stamen (male) + carpel (female).
A typical flower has 4 parts (from outside in):
1. Sepals. Green; protect the bud before flowering. Often fall off as the flower opens.
2. Petals. The colourful display.
3. Stamen (male part).
4. Carpel (female part, also called pistil).
Most flowers have BOTH male and female parts — they're 'hermaphrodite' or 'bisexual'. Some species have separate male/female flowers (e.g. squash, holly).
Worked qualitative. Why are bee-pollinated flowers often blue/purple, while bird-pollinated flowers are often red?
Cambridge tip. Memorise the four parts and which is male/female. Cambridge often gives a labelled diagram and asks to identify or describe roles.
Different vectors → very different flowers.
Insect-pollinated flowers:
| Feature | Reason |
|---|---|
| Brightly coloured petals | Attract insects |
| Scented | Attract insects |
| Nectar (sweet liquid) | Reward for insect visit |
| Sticky pollen | Sticks to insect body |
| Sticky stigma INSIDE the flower | Catches pollen brought in |
| Small amounts of pollen | Few but precise transfers |
Wind-pollinated flowers:
| Feature | Reason |
|---|---|
| Small, dull petals (or absent) | No need to attract insects |
| No scent or nectar | Same |
| Light, dry, smooth pollen | Carried easily by wind |
| Lots of pollen | Most blows away; need extras |
| Anthers OUTSIDE the flower (dangling) | Pollen released into the air |
| Feathery stigma OUTSIDE the flower | Catches drifting pollen |
Examples.
Hay fever — wind-pollinated plants release LOTS of pollen, which causes allergic reactions in some people.
Worked qualitative. Why do farmers introduce BEEHIVES into orchards during flowering?
Cambridge tip. Pair each adaptation with its REASON. Cambridge marks both halves.
Same plant or different plant. Cross gives more variation.
Self-pollination.
Cross-pollination.
How plants encourage cross-pollination.
After pollination — fertilisation.
Worked qualitative. Why do many flower species REFUSE their own pollen?
Cambridge tip. Memorise the chain after pollination: pollen tube → ovule → fertilisation → zygote → seed; ovary → fruit.
Verbatim phrases and definitions Cambridge mark schemes credit.
Plant reproduction appears Paper 4 (5-8 marks: label flower, contrast pollination vectors, describe fertilisation). Examiner reports flag students confusing stamen/carpel and pollination/fertilisation.
Sources: Cambridge IGCSE Biology 0610 syllabus 2026-2028 (16.3); 0610/22 May/Jun 2024 — Q11 (plant reproduction); 0610 Examiner Reports 2022-2024. Last reviewed 2026-05-07.
Step-by-step solutions to past-paper-style questions on sexual reproduction in plants, written exactly the way a tutor would explain them at the board.
Question
Name the main parts of an insect-pollinated flower and give the function of each.
Step-by-step solution
Step 1
Sepals: protect the flower while it is a bud.
Step 2
Petals: brightly coloured to attract insects.
Step 3
Stamen (male part): the anther makes pollen; the filament holds it up.
Step 4
Carpel (female part): the stigma receives pollen; the style holds it up; the ovary contains the ovules (which contain the female gametes).
Answer
Sepals (protect the bud), petals (attract insects), stamen = anther (makes pollen) + filament, carpel = stigma (receives pollen) + style + ovary (contains ovules).
Question
State which part of a flower: (a) produces pollen; (b) receives pollen; (c) contains the ovules.
Step-by-step solution
Step 1
(a) Produces pollen → the anther (part of the male stamen).
Step 2
(b) Receives pollen → the stigma (top of the female carpel).
Step 3
(c) Contains the ovules → the ovary (part of the female carpel).
Answer
(a) Anther; (b) stigma; (c) ovary.
Examiner tip
The anther MAKES pollen (male); the stigma RECEIVES it (female). Don't swap them.
Question
Compare the flowers of insect-pollinated and wind-pollinated plants.
Step-by-step solution
Step 1
Insect-pollinated flowers have large, brightly coloured, scented petals (and often nectar) to attract insects.
Step 2
Their pollen is sticky or spiky (to attach to insects), and the stigma is sticky and inside the flower.
Step 3
Wind-pollinated flowers are small, dull and have no scent or nectar.
Step 4
They produce large amounts of light, smooth pollen, and have anthers and feathery stigmas that hang outside to catch pollen blown in the wind.
Answer
Insect-pollinated: bright scented petals, sticky pollen, sticky stigma inside. Wind-pollinated: small dull flowers, lots of light pollen, feathery stigmas outside.
Examiner tip
Cambridge wants each feature linked to its reason — e.g. 'bright petals to attract insects'.
Question
Define self-pollination and cross-pollination, and state which produces more variation.
Step-by-step solution
Step 1
Self-pollination is the transfer of pollen from the anther to the stigma of the same flower (or another flower on the same plant).
Step 2
Cross-pollination is the transfer of pollen from the anther of one plant to the stigma of a flower on a different plant of the same species.
Step 3
Cross-pollination brings together genes from two different plants, so it produces more genetic variation.
Answer
Self-pollination: pollen to the same plant. Cross-pollination: pollen to a different plant. Cross-pollination gives more variation.
Question
Describe what happens after a pollen grain lands on the stigma, leading to fertilisation.
Step-by-step solution
Step 1
After landing on the stigma, the pollen grain grows a pollen tube.
Step 2
The pollen tube grows down through the style towards the ovary.
Step 3
It enters an ovule, and the male gamete nucleus travels down the tube.
Step 4
The male gamete nucleus fuses with the female gamete nucleus in the ovule — this is fertilisation — forming a zygote, which develops into a seed.
Answer
The pollen grain grows a pollen tube down the style to an ovule; the male gamete nucleus travels down it and fuses with the female gamete nucleus (fertilisation), forming a zygote that becomes a seed.
Examiner tip
The pollen tube carries the male gamete to the ovule. Fertilisation is the FUSION of the gamete nuclei.
Question
After fertilisation, explain what the ovule and the ovary become, and why this matters for the plant.
Step-by-step solution
Step 1
After fertilisation, the zygote inside the ovule develops into an embryo.
Step 2
The whole ovule becomes a seed, which contains the embryo and a food store.
Step 3
The ovary becomes a fruit, which surrounds and protects the seed(s).
Step 4
This matters because the seeds can be dispersed away from the parent plant, reducing competition and allowing the species to spread to new areas.
Answer
The fertilised ovule becomes a seed (containing the embryo and food store) and the ovary becomes a fruit. The seeds can then be dispersed, helping the plant spread and reducing competition.
Examiner tip
Ovule → seed; ovary → fruit. The fruit protects the seeds and helps with dispersal.
High-scoring sample answers for sexual reproduction in plants on the Cambridge IGCSE 0610 paper, with examiner-style notes mapping each response to the mark scheme and assessment objectives.
Define pollination. (1 mark)
Model answer
Pollination is the transfer of pollen grains from the anther to the stigma.
Why this scores
One mark for 'transfer of pollen from anther to stigma'.
Name the male part and the female part of a flower. (2 marks)
Model answer
The male part is the stamen (anther and filament). The female part is the carpel (stigma, style and ovary).
Why this scores
One mark each: stamen (male); carpel (female). Naming the anther and stigma also acceptable.
State three features of an insect-pollinated flower and give the reason for each. (3 marks)
Model answer
It has large, brightly coloured petals to attract insects; it produces nectar (and scent) to attract and reward insects; and it has sticky or spiky pollen that attaches to the insect's body so it is carried to another flower.
Why this scores
Three marks, each a feature paired with its reason (e.g. bright petals → attract insects).
Explain the difference between self-pollination and cross-pollination, and state which produces more genetic variation. (4 marks)
Model answer
Self-pollination is the transfer of pollen from the anther to the stigma of the same flower or another flower on the same plant. Cross-pollination is the transfer of pollen from the anther of a flower on one plant to the stigma of a flower on a different plant of the same species. Cross-pollination produces more genetic variation, because the offspring receive genes from two different parent plants.
Why this scores
Four marks: self = same plant; cross = different plant of the same species; cross gives more variation; because genes come from two different plants.
Describe how fertilisation takes place after a pollen grain has landed on the stigma. (5 marks)
Model answer
The pollen grain on the stigma grows a pollen tube. The pollen tube grows down through the style towards the ovary. It enters an ovule through a small opening. The male gamete nucleus passes down the pollen tube into the ovule, where it fuses with the female gamete nucleus. This fusion is fertilisation, and it forms a zygote, which develops into the embryo of a seed.
Why this scores
Five marks: pollen tube grows; down the style to the ovary; enters an ovule; male gamete nucleus travels down/fuses with the female gamete nucleus; forms a zygote.
Compare the features of an insect-pollinated flower with those of a wind-pollinated flower, explaining how each is suited to its method of pollination. (6 marks)
Model answer
An insect-pollinated flower has large, brightly coloured, scented petals and often nectar, which attract insects to visit it. Its anthers are inside the flower, where they brush pollen onto the visiting insect, and its pollen is sticky or spiky so it sticks to the insect's body; its stigma is also sticky and inside the flower to pick the pollen off the next insect. A wind-pollinated flower, in contrast, is small, dull and has no scent or nectar, because it does not need to attract insects. It produces large amounts of light, smooth pollen that is easily carried by the wind, and its anthers and feathery stigmas hang outside the flower, where the anthers release pollen into the air and the large feathery stigmas have a big surface area to catch pollen blown past. So each type of flower has features suited to whether it is pollinated by insects or by the wind.
Why this scores
Up to 6 marks: insect — bright/scented petals + nectar (attract insects), pollen sticky/spiky, stigma sticky and inside; wind — small/dull/no scent, lots of light pollen, anthers and feathery stigmas outside/exposed. Reward linking features to the pollination method.
Definitions to memorise and the exact keywords mark schemes credit for sexual reproduction in plants answers — sharpened from recent examiner reports for the 2026 0610 sitting.
The transfer of pollen grains from the anther (male) to the stigma (female).
The male part of a flower: the anther (makes pollen) and the filament.
The female part of a flower: the stigma, style and ovary. The ovary contains the ovules.
Transfer of pollen to the stigma of the same flower, or another flower on the same plant.
Transfer of pollen to the stigma of a flower on a different plant of the same species. Gives more variation.
The fusion of the male gamete nucleus (from the pollen) with the female gamete nucleus in the ovule, forming a zygote.
The traps other students keep falling into on sexual reproduction in plants questions — taken from recent Cambridge IGCSE 0610 examiner reports and mark schemes — and how to avoid them.
Why it happens
Both involve the gametes.
How to avoid it
POLLINATION is the transfer of pollen to the stigma. FERTILISATION is the later fusion of the gamete nuclei in the ovule.
Why it happens
All flowers seem attractive.
How to avoid it
Wind-pollinated flowers are small, dull and scentless — they do not need to attract insects. Only insect-pollinated flowers are bright and scented.
Why it happens
Both are reproductive parts.
How to avoid it
The ANTHER produces pollen (male). The STIGMA receives pollen (female).
The things students keep getting wrong in this sub-topic, answered.