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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
With the help of a suitable example, explain protandry.
Describe the characteristic features of wind pollinated flowers.
Why angiosperm anthers are called dithecous?
What is self-incompatibility?
Draw a diagram of a section of a megasporangium of an angiosperm and label funiculus, Micropyle, embryosac and nuclleus.
Write two ways in which pollination may occur in plants.
Name two characteristics of flowers in which pollination occur by wind.
Complete the following chart and rewrite.
| Sr.No. | Agencies | type of pollination |
| 1 | Water | .................... |
| 2 | ........................... | Entomophily |
| 3 | Bat | .................... |
| 4 | ....................... | Ornithophily |
(Or)
Explain outbreeding devices in angiospermic plants.
Select and write the most appropriate answer from the given alternatives for the following subquestion:
A versatile anther is an adaptation for _______ type of pollination.
Name of the part of the ovary which gives rise to:
Fruit ______
Give one word/term for the following:
Pollination of flowers by insects.
Type of Interaction where an individual sacrifices its own welfare (life) for the benefit of another animal of its own species is ______.
Give four adaptations shown by flowers pollinated by wind.
Answer the following question.
Express the process of pollination in Vallisneria.
Differentiate between geitonogamy and xenogamy (allogamy).
- Nucellus
- Antipodals
- Synergids
- Micropyle
Describe pollination. How many types of pollinations are found?
Differentiate Between Cross Pollination and Self Pollination:
Very short answer type question:
What is hydrophily?
What are the different adaptations shown by bird-pollinated flowers?
Explain water pollination in detail with its types.
Give an account of any two biotic agents for pollination along with their adaptations.
From among the situations given below, choose the one that prevents both autogamy and geitonogamy.
Cleistogamous flowers are ______.
Both chasmogamous and cleistogamous flowers are present in ______.
Which of the following pair has haploid structures?
Heterostyly as a contrivance for cross-pollination is found in ______.
Describe any three adaptations in hydrophilous flowers.
Give any four floral adaptations for chiropterophily.
