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💡 Getting pollen to the right place
Pollen sits on the anther, but the egg waits inside the pistil. Somehow the pollen must travel to the stigma — and nature has clever ways to move it.
What is pollination?
Pollination
The transfer of pollen grains from the anther to the stigma of a flower. Leads to fertilisation, fruits and seeds
- Pollination is the transfer of pollen grains from the anther to the stigma of a flower.
- It is essential for the formation of fruits and seeds .
- It happens through various strategies provided by nature.
Activity 11.6 — Let us investigate
In this Activity, we will investigate the role of pollination by covering pea flowers and comparing fruit formation.
Activity 11.6 — Pollination
Step 1
Select pea buds and open flowers
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Step 2
Remove stamens from some flowers
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Step 3
Wrap several in muslin bags, leave one open
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Step 4
Watch which flowers form fruits
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No stamens → no fruit; pollen is needed
- Identify sweet pea (matar) plants in a garden or field.
- Select two juvenile flower buds and three freshly blossomed flowers on the same plant.
- Remove the stamens from one bud and one open flower.
- Loosely wrap muslin cloth bags around the bud, the bud with stamens removed, the flower with stamens removed and a freshly blossomed flower; leave one open flower uncovered.
- Observe fruit development, then note your observations in Table 11.2.
What we observe
Fruits form in all treatments
except the one where the stamens were removed
— showing that transfer of pollen is necessary for fruit formation.
| Treatments | Flower bud (wrapped with muslin cloth bag) | Flower bud with removed stamens (wrapped with muslin cloth bag) | Flower with removed stamens (wrapped with muslin cloth bag) | Flower (wrapped with muslin cloth bag) | Flower (without muslin cloth bag) |
|---|---|---|---|---|---|
| Fruit formation (Yes/No) |
What are self-pollination and cross-pollination?
Types of Pollination
Self-pollination — Cross-pollination pollen to the same — pollen to a or another flower flower on a on the same plant different plant of the same kind
- In self-pollination , pollen reaches the stigma of the same flower or another flower of the same plant (Fig. 11.13).
- In cross-pollination , pollen is transferred from a flower of one plant to the stigma of a flower of another plant of the same type.
- Both deliver pollen to the stigma, but cross-pollination mixes characters from two different plants.
NCERT Question 1 — A flower’s anthers are removed
A flower’s anthers are removed before it matures. Later, pollen from another plant of the same species is dusted onto its stigma and seeds are produced. Which process has been ensured here? (i) Self-pollination (ii) Cross-pollination (iii) Fertilisation (iv) Tissue culture
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NCERT Question 8 — If all flowers in a
If all flowers in a type of plant were only capable of self-pollination, how would it affect the genetic diversity over several generations? Explain.
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NCERT Question 10 — Suresh prepares slides with pollen
Suresh prepares slides with pollen grains in different sugar concentrations (0%, 2.5%, 5%, 7.5%, 10%) to study the germination of pollen. (i) What are the different hypotheses which can be tested using this set-up? (ii) What parameters should be kept the same in this set-up?
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Important Definitions
- Pollination — the transfer of pollen grains from the anther to the stigma.
- Self-pollination — pollen reaching the stigma of the same flower, or of another flower on the same plant.
- Cross-pollination — pollen from one plant reaching the stigma of another plant of the same type.
