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प्रश्न
What is self-incompatibility?
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उत्तर
Self-incompatibility is a genetic mechanism in angiosperms that prevents self-pollination. It develops genetic incompatibility between individuals of the same species or between individuals of different species. The pollen grains of an anther do not germinate on the stigma of the same flower.
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संबंधित प्रश्न
With the help of a suitable example, explain protandry.
As a senior biology student you have been asked to demonstrate to the students of secondary level in your school, the procedure(s) that shall ensure cross-pollination in a hermaphrodite flower. List the different steps that you would suggest and provide reasons for each one of them.
Why do moss plants produce very large number of male gametes? Provide one reason. What are these gametes called?
Geitonogamous flowering plants are genetically autogamous but functionally cross-pollinated. Justify.
Why angiosperm anthers are called dithecous?
Can cross-pollination occur in cleistogamous flowers? Give reasons for your answer.
Add a note on pollination mechanism in Salvia.
The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as ______.
Describe the structure of its microsporangium.
Can a plant flowering in Mumbai be pollinated by pollen grains of the same species growing in New Delhi? Provide explanations to your answer.
Give an account of any two biotic agents for pollination along with their adaptations.
A particular species of plant produces light, non-sticky pollen in large numbers and its stigmas are long and feathery. These modifications facilitate pollination by ______.
Pollination by water occurs in ______.
Heterostyly as a contrivance for cross-pollination is found in ______.
Pollination refers to the ______.
What is ornithophily?
Consider the following statements depicting adaptation of flowers to carryout successful pollination.
- Stigma is long, sticky and unwettable.
- Sepals, petals or perianth (if present) have waxy coating.
- Stamens with long filament and versatile anthers.
- Tubular corolla is seen.
- Flowers are noctumal.
Which of the above statements clearly depict hydrophily?
Mention any one example of the anemophilous flower.
Name the following:
One plant each of Hypohydrophily and epihydrophily.
Identify the set of correct statements:
- The flowers of Vallisneria are colourful and produce nectar.
- The flowers of waterlily are not pollinated by water.
- In most of water-pollinated species, the pollen grains are protected from wetting.
- Pollen grains of some hydrophytes are long and ribbon like.
- In some hydrophytes, the pollen grains are carried passively inside water.
Choose the correct answer from the options given below:
