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प्रश्न
Why does self-pollination not lead to seed formation in self-incompatible species?
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उत्तर
Self-incompatibility is a gene-physiological event. A single gene, known as the S-gene, regulates incompatibility reactions and contains many alleles. Pollen grains with the S-allele, which is shared by either of the two alleles in pistil cells, won’t work on that pistil However, any pollen grain that does not share S alleles with the pistil will function on that plant’s pistil. Self-pollens are unable to fertilize the egg, resulting in the formation of an embryo; hence, seeds do not form in incompatible species.
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संबंधित प्रश्न
Describe the characteristic features of wind pollinated flowers.
Can cross-pollination occur in cleistogamous flowers? Give reason for your answer.
Mention two strategies that evolved to prevent self-pollination in flowers.
Enlist advantages and disadvantages of cross pollination
Give the floral adaptations for anemophily.
Name two characteristics of flowers in which pollination occur by wind.
Fill in the blank:
Male sex cells in plants are called _________.
Which one of the following is one of the characteristics of self-pollinated flowers?
Fill in the blanks with suitable words.
_______ is a water-pollinated flower.
Give one word/term for the following:
When stigma and anthers do not grow up to the same height, which favors only cross-pollination.
Give one word/term for the following:
Pollination of flowers by birds.
What are the adaptations which are required in cross-pollinated
Give an account of various abiotic agencies used in pollination along with their adaptations for pollination.
For which of the following attractants and rewards are required?
Autogamy can occur in a chasmogamous flower if ______.
Wind pollination is common in ______.
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 ______.
Flowers which have single ovule in the ovary and are packed into inflorescence are usually pollinated by ______.
Even in absence of pollinating agents seed-setting is assured in ______.
In the dioecious aquatic plant shown, identify the characteristics of the male flowers that reach the female flowers for pollination:
| Size of the flower | Colour of flower | The characteristic feature of pollen grain | |
| A | small | brightly coloured | Lightweight and non-sticky |
| B | large | colourless | large and sticky |
| C | small | white | small, covered with mucilage |
| D | large | colourless | non-sticky |
A botanist studying Viola (common pansy) noticed that one of the two flower types withered and developed no further due to some unfavorable condition, but the other flower type on the same plant survived and it resulted in an assured seed set. Which of the following will be correct?
The term used for transfer of pollen grains from anthers of one plant to stigma of a different plant which, during pollination, brings genetically different types of pollen grains to stigma, is ______
What is self-incompatibility?
Pollination in water lilies is carried out by ______.
Describe any three adaptations in hydrophilous flowers.
Mention any one example of the hydrophilous flower.
When and why does a plant breeder employ the emasculation technique?
