BiologyICSE Class 9 · Pollination

Self and Cross Pollination and Agents of Pollination (ICSE Class 9 Biology)

Updated 17 October 2026 · Fact-checked

Pollination is the transfer of pollen from an anther to a stigma. In self-pollination the pollen reaches a stigma of the same flower; in cross-pollination it reaches a flower of another plant of the same species. Agents are insects (entomophily), wind (anemophily) and water (hydrophily), and flowers are adapted to the agent that carries their pollen.

Understand Self and Cross Pollination and Agents of Pollination

1. Self-pollination (autogamy). Pollen from the anther falls on the stigma of the same flower. It needs no agent and is sure, but gives little variation and weaker offspring over generations. It occurs in bisexual flowers whose stamens and pistil mature together, as in pea and wheat.

2. Cross-pollination (allogamy). Pollen goes to the stigma of a flower on a different plant of the same species. It needs an agent but gives variation and vigorous seeds that can adapt better, though it wastes pollen.

3. Insect pollination (entomophily). Flowers are large, brightly coloured and scented, with nectar; pollen is sticky or spiny and sticks to the insect's body; the stigma is sticky. Example: sunflower, rose, mustard.

4. Wind pollination (anemophily). Flowers are small, dull, without scent or nectar; anthers hang out on long filaments; pollen is light, dry and produced in huge numbers; the stigma is feathery and often protrudes. Example: maize, wheat, grasses.

5. Water pollination (hydrophily). In water plants such as *Vallisneria* and *Hydrilla*, pollen is carried by water currents; pollen is protected from wetting and the stigma is receptive on the water surface.

6. How nature favours cross-pollination. Unisexual flowers (male and female flowers separate); *dichogamy* (anthers and stigma mature at different times); *self-sterility* (pollen of the same flower cannot fertilise); and structural barriers such as stigma placed above the anthers.

Self and Cross Pollination and Agents of Pollination: key facts

Self pollination: Same flower
No agent
Less variation
Assured
Cross pollination: Different plant, same species
Needs an agent
Variation
Wastage of pollen
Insect flowers: Bright colour
Scent
Nectar
Sticky pollen and stigma
Wind flowers: Small
Dull
Light pollen in large amount
Feathery stigma
Exposed anthers

Self and Cross Pollination and Agents of Pollination in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Garden visit

Suppose a garden has roses, maize and a pond with Vallisneria; students notice bees on roses but none on maize.

Explain the difference in pollination.

Try it first, then show the solutionSolution

Roses are bright, scented and have nectar to attract bees.
Maize has light pollen and feathery stigma for wind pollination.
Vallisneria depends on water.

Answer: Rose: insects; maize: wind; Vallisneria: water.

Memory hook: Colour calls bees, feathers catch wind.

Tricks to remember Self and Cross Pollination and Agents of Pollination

Short memory aids. Say each one aloud once, then use it on a question the same day.

Bright = Bees
Bright, scented flowers draw insects; dull small flowers rely on wind.
Use it when: Agent identification.
Auto = same
Autogamy: same flower; allogamy: another.
Use it when: Types.

Self and Cross Pollination and Agents of Pollination: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Define · 2 marks · Short answerBoard level

Define pollination and name its two types. [2]

Try it first, then show the solutionSolution

Transfer of pollen from anther to stigma.
Self and cross pollination.

Answer: Pollen transfer from anther to stigma; self and cross.

Example 2: Wind adaptations · 3 marks · Short answerHarder board level

State three adaptations of a wind-pollinated flower with a reason for each. [3]

Try it first, then show the solutionSolution

Light, dry pollen in huge quantity: carried far and compensates for loss.
Feathery stigma: traps pollen from the air.
Exposed anthers: shed pollen into the wind.

Answer: Light pollen, feathery stigma and exposed anthers suit wind carriage.

Example 3: Greenhouse puzzle · 3 marks · Short answerHarder board level

A farmer grows tomatoes in a closed greenhouse and gets poor fruit set. Suggest why and one remedy. [3]

Try it first, then show the solutionSolution

Pollen may not move without wind or insects.
Flowers need to be shaken or hand pollinated.
Letting insects in or shaking the plants helps.

Answer: Lack of pollinators; hand pollination or insects.

Example 4: Dichogamy · 3 marks · Short answerHarder board level

Explain how dichogamy prevents self-pollination in a bisexual flower. [3]

Try it first, then show the solutionSolution

Anthers and stigma mature at different times.
When pollen is ripe the stigma is not ready, or the reverse.
So pollen from another flower must pollinate.

Answer: The sexual parts mature at different times, so self-pollination is avoided.

Example 5: Case: a flowering pond · 6 marks · Case-basedHOTS / competency

Case. A pond plant has small flowers that float; its pollen is carried by water. (i) Name the type of pollination. [1] (ii) Name one such plant. [1] (iii) Why must its pollen be protected? [2] (iv) Why is this plant unlikely to depend on insects? [2]

Try it first, then show the solutionSolution

(i) Hydrophily.
(ii) Vallisneria.
(iii) Water could damage or wash the pollen away.
(iv) Its flowers are on the water surface with no need for colour or scent.

Answer: (i) Hydrophily (ii) Vallisneria (iii) To prevent wetting (iv) Floating flowers use water currents.

Where students lose marks in Self and Cross Pollination and Agents of Pollination

The slips examiners see most often, and what to write instead.

Mistake: Writing that pollination is fertilisation
Terms are confused.
Do this: Pollination is transfer; fertilisation is fusion.
Usually costs: 1 mark.
Mistake: Saying wind flowers are scented
Adaptations are mixed.
Do this: Wind flowers are small and unscented.
Usually costs: 1 mark.
Mistake: Listing advantages without the other type
No comparison.
Do this: Always state both types.
Usually costs: 1 mark.

Exam tips

Write a table for entomophilous and anemophilous flowers.
Mention at least one example for each agent.
Link each adaptation to its reason.
Draw an arrow from anther to stigma in diagrams.

Practice questions on Self and Cross Pollination and Agents of Pollination

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
A flower with a feathery stigma is likely to be pollinated by:
(a) insects
(b) wind
(c) birds
(d) water
Hint
Catch pollen.
Answer
(b) wind.
Q2 · 2 marks · Very short answerBoard level
Name two agents of pollination other than insects. [2]
Hint
Air and water.
Answer
Wind and water (also birds and animals).
Q3 · 2 marks · Very short answerBoard level
What is the role of nectar in insect-pollinated flowers? [2]
Hint
Reward.
Answer
It attracts insects, which carry pollen while feeding.
Q4 · 1 mark · Assertion-reasonHarder board level
Assertion (A): Cross-pollination produces healthier plants than self-pollination.
Reason (R): Cross-pollination combines characters of two parent plants.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Hint
Variation.
Answer
(a).
Q5 · 4 marks · Long answerBoard level
Compare entomophilous and anemophilous flowers on size, scent, pollen and stigma. [4]
Hint
Table.
Answer
Insect flowers: large, scented, sticky pollen and sticky stigma; wind flowers: small, unscented, light dry pollen and feathery stigma.
Q6 · 2 marks · Very short answerHarder board level
Why do wind-pollinated plants produce more pollen than insect-pollinated plants? [2]
Hint
Chance.
Answer
Wind carries pollen at random, so many grains are lost.
Q7 · 2 marks · Very short answerHarder board level
Pea flowers are self-pollinated but still make healthy seeds. Give two advantages of self-pollination to the plant. [2]
Hint
Guarantee.
Answer
It does not need an agent and ensures seed formation.
Q8 · 3 marks · Case-basedHOTS / competency
Case. A flower has the stigma above the anthers and male and female flowers on different plants. (i) Which pollination does this favour? [1] (ii) Name the arrangement of flowers on different plants. [1] (iii) Give a similar adaptation. [1]
Hint
Separate.
Answer
(i) Cross-pollination. (ii) Unisexual flowers on separate plants. (iii) Dichogamy or self-sterility.
Q9 · 3 marks · Long answerHOTS / competency
Case. A student sees a night-blooming white scented flower visited by moths. Suggest, giving three reasons, why the flower is white and scented. [3]
Hint
Visibility at night.
Answer
White shows in dim light; scent guides the moth; nectar is a reward, so moths carry pollen.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Pollination agent in maize?Show answer
Wind.
2.Water pollinated plant?Show answer
Vallisneria.
3.What is dichogamy?Show answer
Anthers and stigma mature at different times.
4.Another name for self-pollination?Show answer
Autogamy.
5.Which pollination gives variation?Show answer
Cross-pollination.

Self and Cross Pollination and Agents of Pollination: frequently asked questions

Is geitonogamy self or cross?

It is between flowers of the same plant and is genetically like self-pollination.

Can birds pollinate?

Yes, some flowers are pollinated by birds.

Why are petals coloured?

To attract pollinators.